FIGURE 1.

The novel cell adhesion apparatus mediated by nectin-1 and nectin-4 as a platform for cellular signaling in the mammary gland. A, schematic of the mammary gland. The adult mammary gland, consisting of collecting ducts and alveoli, is composed of a bilayer structure of inner luminal cells surrounded by outer basal myoepithelial cells with the outermost side ensheathed by the basement membrane. B, schematic of the findings. A novel cell adhesion apparatus mediated by nectins was found at the boundary between the luminal and basal cells in addition to desmosomes. The nectin-mediated adhesion apparatus identified here may serve as a platform for cellular signaling.