Plays a role in the formation of tricellular tight junctions and of epithelial barriers (By similarity). Required for normal hearing via its role in the separation of the endolymphatic and perilymphatic spaces of the organ of Corti in the inner ear, and for normal survival of hair cells in the organ of Corti (PubMed:17186462). Interacts with TJP1 (PubMed:17186462). Interacts with the ubiquitin ligase ITCH (PubMed:28436082). Interacts (via C-terminal cytoplasmic domain) with LSR (via the cytoplasmic domain), ILDR1 and ILDR2; the interaction is required to recruit MARVELD2 to tricellular contacts (By similarity). Located at tricellular contacts. Ubiquitinated by ITCH; but this ubiquitination does not lead to proteasomal degradation. Phosphorylated. The disease is caused by variants affecting the gene represented in this entry. Belongs to the ELL/occludin family.