Current functional bioinformatics approaches are handicapped by the inability to store functional data at all or by a scattering of data across heterogeneous databases that are difficult to link and query. The Cellular Response Database (CRD) (http://LHI5.umbc.edu/crd) is designed to store and retrieve data concerning changes in in vitro cellular functions associated with stimuli, such as cytokines and drugs. The database can store a broad range of data, including protein or mRNA expression, as well as functional cellular data, such as apoptosis or adherence. This unique ability to store heterogeneous data using a single data model will minimize difficulties associated with searching multiple databases. Authors with articles accepted by participating journals are invited to submit data to the CRD. Submission instructions are outlined, along with a review of the CRD's development.