LAMB2 and sarcoma: The laminins that have traditionally been commercially available are laminin 111 (from Engelbreth-Holm-Swarm murine sarcoma basement membrane), a mixture of laminin 211 and laminin 221 (from human placenta), or a mixture of various laminin isoforms (pepsinized human laminin), which are not specific to the BM of endothelial cells.