Provides centralized Affymetrix expression profiling data to the public research community, typically before publication in primary research papers. Data released through PEPR are generated within a single centralized research group (Children’s National Medical Center, Microarray Center), with projects originating internally and referred from external institutions. The web interface enables users to export many forms of data associated with any particular profile, including raw image files (.dat), processed image files (.cel) and interpretation files (.txt). It allows researchers to perform on‐line queries of expression profiles by any number of experimental variables (tissue, species, chip type, etc.).