Tricellulin is the first molecular component of tricellular tight junctions at tricellular contacts where three epithelial cells meet, and it is required for the their formation and maintenance of the epithelial barrier. Tricellulin binds other tight junction proteins, and its expression and distribution are affected by the bicellular tight junction protein occludin and lipolysis-stimulated lipoprotein receptor (LSR) which is expressed at tricellular contacts. Tricellulin is also detected in endothelial cells, neurons, microglia and astrocytes. Here, we focused tricellulin expression in various types of epithelial cells, nasal epithelial cells, pancreatic duct epithelial cells cells and hepatocytes, and non-epithelial cells, dendritic cells and Schwann cells, compared to expression of the bicellular tight junction protein occludin and LSR, and discuss the regulation and the role of tricellulin in cellular specificity.