CADM1 mediates homophilic cell-cell adhesion in a Ca2+-independent manner and also mediates heterophilic cell-cell adhesion with CADM3 and PVRL3 in a Ca2+-independent manner. This protein acts as a tumor suppressor in non-small-cell lung cancer (NSCLC) cells. Interaction with CRTAM promotes natural killer (NK) cell cytotoxicity and interferon-gamma (IFN-gamma) secretion by CD8+ cells in vitro as well as NK cell-mediated rejection of tumors expressing CADM3 in vivo. Recombinant human CADM1 protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.