Component of intercellular desmosome junctions. Involved in the interaction of plaque proteins and intermediate filaments mediating cell-cell adhesion. May contribute to epidermal cell positioning (stratification) by mediating differential adhesiveness between cells that express different isoforms. First expressed at 13.0 dpc in epithelium of whisker pads and external nares, and in most mature vibrissa follicles. 12 hours later, prominently expressed in whiskers and tactile follicles above the eye. At 14.5 dpc, also expressed in developing nails and teeth and, at low levels, in ventral and lateral skin. At 15.5 dpc, highly expressed in general body epidermis and at 16.5 dpc, detected over entire embryo. In the adult, highly expressed in basal layers of stratified cells. Calcium may be bound by the cadherin-like repeats. Three calcium ions are usually bound at the interface of each cadherin domain and rigidify the connections, imparting a strong curvature to the full-length ectodomain.