Owing to heterophilic interactions between JAM-A, JAM-B, and JAM-C and the leukocyte integrins LFA-1, VLA-4, and Mac-1, respectively, JAMs may also contribute to transmigration of leukocytes and tumor cells through the liver-specific transendothelial barrier established by LSECs. The gene discussed is JAM2; the disease is neoplasm.