Information about submitted studies, summary level data, and documents related to studies can be accessed freely on the dbGaP website (http://www.ncbi.nlm.nih.gov/gap). Individual-level data can be accessed only after a Controlled Access application, stating research objectives and demonstrating the ability to adequately protect the data, has been approved (https://dbgap.ncbi.nlm.nih.gov/aa/wga.cgi?page=login). Public summary data from dbGaP are also accessed without restriction via the PheGenI tool, as detailed in the Related tools section.