# STRING

License: permissive (CC-BY-4.0); Mdexa hosting: link-only. Second pass: license_status: looser by the source's own words (looser-explicit): 【标准许可误作自定义条款】条款页明写全部数据与下载文件采用 CC BY 4.0，并明说可用于商业用途、可用于 AI 训练、衍生文件可再分发。快照中没有甲类句："其他来源的材料仍受原提供方条款约束"属丙类（设 third_party_rights_notice，不降级，第23条），"请勿抓取 HTML""限量访问"属乙类行为义务。按原文应为 permissive（标识 CC-BY-4.0，而非 LicenseRef-STRING-Consortium-terms）；比拟定更宽，按第25条只在原文明示许可时放宽，此处原文明示，交采纳环节放宽，脚本不会自动放宽。 | commercial_use: looser by the source's own words (looser-explicit): 原文明示 "including commercial use"，唯一条件是署名（乙类）。署名不使商用变成 conditional，按原文应为 yes；比拟定更宽，交采纳环节决定。

- Commercial use: Yes · Derivatives: Yes · Redistribution: Yes · File on Mdexa: No
- License status: Permissive (CC-BY-4.0)
- Mdexa hosting: Link only — License permissive, judged by public rules and checked by a second-pass model. Link only.
- Last verified: 2026-11-14
- Card: https://mdexa.com/datasets/string/

## Key facts

- Domain: Genomics and omics
- Content type: Databases
- Size: — — 59'309'604 proteins from 12535 organisms
- Language: English
- Modality: Tabular, Graph
- Publisher: STRING Consortium
- Year: September 29, 2026

## Commercial use of STRING

- Commercial use: Yes.
The overall verdict takes the strictest part; the parts carry different licenses, listed below.
- License status: Permissive.
- Conditions: Attribution
- License part: main data — Permissive (NOASSERTION)
- License part: STRING data and download files — Permissive (CC-BY-4.0)
Verdicts record what sources state and are not legal advice.

## STRING license evidence

all parts permissive; conditions are the union of the parts Material from other resources shown in STRING keeps its own terms: check the exceptions before use.

- **Terms of use page** — CC-BY-4.0: Statement found in snapshot s02 (page) — "All data and download files in STRING are freely available under the Creative Commons Attribution 4.0 (CC BY 4.0) license." — https://string-db.org/cgi/access (2026-11-13; Page opened)
- **Terms of use page**: Statement found in snapshot s02 (page) — "When using the data, please credit STRING and indicate any changes or additions you made to the data." — https://string-db.org/cgi/access (2026-11-13; Page opened)
- **Terms of use page**: Statement found in snapshot s02 (page) — "The license covers the following STRING outputs, whether obtained from the website, the APIs or the download files: network images, functional enrichment graphs, tables, data files, individual scores and data points, and screenshots of the STRING website." — https://string-db.org/cgi/access (2026-11-13; Page opened)
- **Terms of use page**: Statement found in snapshot s02 (page) — "Material from other resources that STRING incorporates or displays remains subject to the terms of its original provider." — https://string-db.org/cgi/access (2026-11-13; Page opened)
- **Terms of use page**: Statement found in snapshot s02 (page) — "No separate permission is needed to publish the STRING outputs listed above." — https://string-db.org/cgi/access (2026-11-13; Page opened)
- **Terms of use page**: Statement found in snapshot s02 (page) — "The license allows their use in any medium and format, print or digital: in open access (CC BY) and subscription journals, books, theses and presentations, including commercial use." — https://string-db.org/cgi/access (2026-11-13; Page opened)
- **Terms of use page**: Statement found in snapshot s02 (page) — "The only condition is attribution: please cite STRING (see References ) and indicate if you modified the material." — https://string-db.org/cgi/access (2026-11-13; Page opened)
- **Terms of use page**: Statement found in snapshot s02 (page) — "STRING outputs may be used in AI applications, such as MCP servers, retrieval-augmented generation (RAG), knowledge graphs and agent tools, and for training or evaluating machine learning models." — https://string-db.org/cgi/access (2026-11-13; Page opened)
- **Terms of use page**: Statement found in snapshot s02 (page) — "Derived files, such as indexes, may also be redistributed given clear attribution to STRING." — https://string-db.org/cgi/access (2026-11-13; Page opened)
- **Terms of use page**: Statement found in snapshot s02 (page) — "Please name STRING and its version as the source in the metadata that accompanies the data, so that an agent can tell where the data came from and cite and link to STRING in its answers." — https://string-db.org/cgi/access (2026-11-13; Page opened)
- **Terms of use page**: Statement found in snapshot s02 (page) — "For trained models, please credit STRING and its version in the model or dataset documentation." — https://string-db.org/cgi/access (2026-11-13; Page opened)
- **Terms of use page**: Statement found in snapshot s02 (page) — "The STRING name and logo may be reproduced without modification to identify STRING as a data source or tool, for example in figures, workflow or pipeline diagrams and presentations, as long as this does not suggest endorsement by the STRING Consortium." — https://string-db.org/cgi/access (2026-11-13; Page opened)
- **Terms of use page**: Statement found in snapshot s02 (page) — "Please bear in mind that this mechanism should only be used for limited or occasional database access, in order to avoid overloading the server." — https://string-db.org/cgi/access (2026-11-13; Page opened)
- **Terms of use page**: Statement found in snapshot s02 (page) — "Please do not scrape the HTML page content." — https://string-db.org/cgi/access (2026-11-13; Page opened)

## Source and lineage

—

## Known issues with STRING

—

## Preflight

Not run (data not ingested).

## Downloading STRING and API access

Mdexa does not serve files. Original source:
- https://string-db.org/
- https://string-db.org/cgi/access

### Access recipe

- Latest: 12.5 (2026-09-29)
- API get_string_ids: `https://string-db.org/api/[output-format]/get_string_ids?identifiers=[your_identifiers]&[optional_parameters]` · example `https://string-db.org/api/tsv/get_string_ids?identifiers=p53%0dcdk2&species=9606`

## Citing STRING

No recommended citation text.

## Machine-readable

- JSON: https://mdexa.com/datasets/string.json
- 2026-11-14 Material from other resources shown in STRING keeps its own terms: check the exceptions before use.
- 2026-11-14 Listed on 2026-11-14. Judged by public rules and checked a second time before listing. The two passes disagreed; the stricter reading is carried: Second pass: license_status: looser by the source's own words (looser-explicit): 【标准许可误作自定义条款】条款页明写全部数据与下载文件采用 CC BY 4.0，并明说可用于商业用途、可用于 AI 训练、衍生文件可再分发。快照中没有甲类句："其他来源的材料仍受原提供方条款约束"属丙类（设 third_party_rights_notice，不降级，第23条），"请勿抓取 HTML""限量访问"属乙类行为义务。按原文应为 permissive（标识 CC-BY-4.0，而非 LicenseRef-STRING-Consortium-terms）；比拟定更宽，按第25条只在原文明示许可时放宽，此处原文明示，交采纳环节放宽，脚本不会自动放宽。 | commercial_use: looser by the source's own words (looser-explicit): 原文明示 "including commercial use"，唯一条件是署名（乙类）。署名不使商用变成 conditional，按原文应为 yes；比拟定更宽，交采纳环节决定。

## Practical information

### Content scope

- The page lists version 12.5 as current since September 29, 2026, with 59,309,604 proteins from 12,535 organisms and 28,464,487,749 interactions.
  > 12.5 current: since September 29, 2026 https://string-db.org/ 59'309'604 proteins from 12535 organisms; 28'464'487'749 interactions.
  https://string-db.org/cgi/access (2026-11-13)
- The entry for version 12.5 lists 28,464,487,749 interactions.
  > 12.5 current: since September 29, 2026 https://string-db.org/ 59'309'604 proteins from 12535 organisms; 28'464'487'749 interactions.
  https://string-db.org/cgi/access (2026-11-13)
- The page asks which databases STRING extracts experimental data from and lists BIND, DIP, GRID, HPRD, IntAct, MINT, and PID.
  > Which databases does STRING extract experimental data from? Top &#x2191 BIND, DIP, GRID, HPRD, IntAct, MINT, and PID.
  https://string-db.org/help/faq/ (2026-11-13)
- The page asks from which databases STRING extracts curated data and lists Biocarta, BioCyc, GO, KEGG, and Reactome.
  > From which databases does STRING extract curated data? Top &#x2191 Biocarta, BioCyc, GO, KEGG, and Reactome.
  https://string-db.org/help/faq/ (2026-11-13)

### Identifiers

- Common protein names, synonyms and UniProt identifiers are mapped into STRING identifiers.
  > Maps common protein names, synonyms and UniProt identifiers into STRING identifiers
  https://string-db.org/help/api/ (2026-11-13)
- The page states that the STRING API can be called using common gene names, synonyms, or UniProt identifiers and accession numbers.
  > You can call the STRING API using common gene names, synonyms, or UniProt identifiers and accession numbers.
  https://string-db.org/help/api/ (2026-11-13)
- The text states that species is the NCBI/STRING taxon identifier, for example 9606 for human.
  > species is the NCBI/STRING taxon identifier, for example 9606 for human
  https://string-db.org/help/api/ (2026-11-13)

### Access

- Web API: https://string-db.org/help/api/
- Web interface only: https://string-db.org/cgi/access
- Web interface only: https://string-db.org/help/faq/

### Versions

- The page lists version 12.5 as current since September 29, 2026.
  > 12.5 current: since September 29, 2026
  https://string-db.org/cgi/access (2026-11-13)

### Known defects and misuse

- The page notes that STRING may not always interpret the original inputs correctly, which can lead to errors or inconsistent results.
  > Note: STRING may not always interpret the original inputs correctly, which can lead to errors or inconsistent results.
  https://string-db.org/help/api/ (2026-11-13)
- Blumenthal et al. report that study bias and technical bias in PPI detection suffice to produce the observed power-law degree distributions; they list STRING among the aggregated PPI databases researchers rely on.
  > Our findings are supported by mathematical models and extensive simulations, and indicate that study bias and technical bias suffice to produce the observed PL distribution.
  https://pmc.ncbi.nlm.nih.gov/articles/PMC11718653/ (2026-11-14)

### Suited for

- The page states that STRING outputs may be used in AI applications such as MCP servers, retrieval-augmented generation, knowledge graphs and agent tools, and for training or evaluating machine learning models.
  > STRING outputs may be used in AI applications, such as MCP servers, retrieval-augmented generation (RAG), knowledge graphs and agent tools, and for training or evaluating machine learning models.
  https://string-db.org/cgi/access (2026-11-13)
- The page states that no separate permission is needed to publish the STRING outputs listed above.
  > No separate permission is needed to publish the STRING outputs listed above.
  https://string-db.org/cgi/access (2026-11-13)
- The page states that the license allows use of the listed outputs in any medium and format, print or digital, in open access and subscription journals, books, theses and presentations, including commercial use.
  > The license allows their use in any medium and format, print or digital: in open access (CC BY) and subscription journals, books, theses and presentations, including commercial use.
  https://string-db.org/cgi/access (2026-11-13)

### Not suited for

- The page directs users who need larger amounts of data, such as all interactions in Homo sapiens, to the Download page instead.
  > If you need larger amounts of data (such as for example all interactions in Homo sapiens), please use the Download page instead - which is also more efficient.
  https://string-db.org/cgi/access (2026-11-13)
- The page states that the Cytoscape backend API is not yet documented and that it is not intended for use other than the Cytoscape App.
  > To make this work, a separate API serves the data to the corresponding 'App' (plugin) in Cytoscape. At present, this API is not yet documented, and we do not recommend it to be used for anything else than the Cytoscape App.
  https://string-db.org/cgi/access (2026-11-13)

### No sourced statement yet

Update cycle, Breaking changes, Commercial licensing

## Continue in this database

This record is one of 109 processed and verified records (datasets, data resources and open models). To find others, call `https://mcp.mdexa.com/v1/datasets?q=<words>` or connect the MCP server at `https://mcp.mdexa.com/mcp`; no key is needed for 20 calls per minute. Rows are under 1 KB; an empty result means "not listed". For a list of items, one batch check (free account) returns a report. Guide: /agents.md. Similar records: AlphaFold Protein Structure Database (https://mdexa.com/datasets/alphafold-db/); GEO (https://mdexa.com/datasets/geo/); gnomAD (https://mdexa.com/datasets/gnomad/).