Probable role in the clearance of triglyceride-rich lipoprotein from blood. Binds chylomicrons, LDL and VLDL in presence of free fatty acids and allows their subsequent uptake in the cells (PubMed:15265030). Maintains epithelial barrier function by recruiting MARVELD2/tricellulin to tricellular tight junctions (PubMed:21245199, PubMed:23239027). Homotrimer or homotetramer (By similarity). Assembles into cell-cell contacts (PubMed:21245199). Interacts (via the cytoplasmic domain) with MARVELD2 (via C-terminal cytoplasmic domain); the interaction is required to recruit MARVELD2 to tricellular contacts (PubMed:21245199, PubMed:23239027). Interacts with OCLN (PubMed:23239027). Located at tricellular contacts. Expressed in eptihelial tissues (at protein level) (PubMed:21245199). Specifically expressed in liver and to a lower extent in kidney (at protein level). Also detected in brain, testis, ovaries, adrenal gland, intestine, muscle, and lung. In colon, only expressed in the lower portion of crypts (PubMed:23239027). Expressed in liver, stomach, small intestine and colon. Also detected in other epithelial tissues. Expressed during embryogenesis (at protein level). Detected from 7.5 dpc to 17 dpc. Phosphorylation at Ser-308 by MAPK8/JNK1 and MAPK9/JNK2 may be required for exclusive localization at tricellular tight junstions. Death between 12.5 dpc and 15.5 dpc probably due to impaired liver and embryonic development. Belongs to the immunoglobulin superfamily. LISCH7 family.