Mammalian Cell Adhesion Molecule (MCAM) is an interactive web-based database containing cell adhesion molecules (CAMs) from the mammalian genome. The MCAM database serves the community of biologists by providing the resources to search for sequence information and other details about CAMs including function and virtual gene expression data available for normal and tumor tissues as well as cell lines. The MCAM contains nucleotide and protein sequences of mouse, human and rat CAMs and includes Gene Ontology (GO), UniGene, UniProt, PIR, SwissProt and OMIM entries. In addition, links to GeneAtlas, GeneCards, NCBI Homologue, CGAP - Gene Finder, UniGene expression profile and GO processes and functions for each gene are provided.