L1CAM and cancer: As partners of integrin β1, integrin α5 and αV are known to bind to L1CAM.33, 34 Similarly to integrin β1 knockdown, integrin α5 knockdown in MDA-MB-231 and A431 cells also abrogated Mint3/L1CAM-dependent cancer cell proliferation by MEFs without affecting cancer cell proliferation itself (Figures 4c and d).