# Data Interoperability ## GTEx Data The Genotype-Tissue Expression (GTEx) Program is a widely used data resource and tissue bank to study the relationship between genetic variants (inherited changes in DNA sequence) and gene expression (how genes are turned on and off) in multiple human tissues and across individuals. For information on access to GTEx data, refer to [GTEx v8 - Free Egress Instructions](https://anvilproject.org/learn/reference/gtex-v8-free-egress-instructions) as part of the [AnVIL](https://anvilproject.org/) documentation. ## NCPI Data Portal The [NIH Cloud Platform Interoperability Effort (NCPI)](https://anvilproject.org/ncpi) is currently working to establish and implement guidelines and technical standards to empower end-user analyses across participating cloud platforms and facilitate the realization of a trans-NIH, federated data ecosystem. Participating institutions include BDC, AnVIL, Cancer Research Data Commons, and Kids First Data Resource Center. Learn what data is currently hosted by these platforms by using the [NCPI Data Portal](https://anvilproject.org/ncpi/data). --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://bdcatalyst.gitbook.io/biodata-catalyst-documentation/written-documentation/data-access/data-interoperability.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.