Component of intercellular desmosome junctions (By similarity). Plays a role in stratified epithelial integrity and cell- cell adhesion by promoting desmosome assembly (By similarity). Thereby plays a role in barrier function of the skin against infection (By similarity). Plays a role in mammary epithelial tissue homeostasis and remodeling during and after pregnancy, potentially via its involvement in desmosome cell-cell junctions (By similarity). Required for tooth enamel development via facilitating desmosome-mediated ameloblast adhesion to the stratum intermedium during the transitional stage of amelogenesis (By similarity). May also play a role in downstream transcriptional regulation of other genes involved in amelogenesis such as AMBN, ENAM, MMP20 and KLK4 (By similarity). Plays a role as an effector in the TP53-dependent apoptotic pathway (By similarity). Positively regulates apoptosis in T-helper 17 (Th17) cell populations via caspase-dependent signaling (By similarity). Promotes neutrophil transepithelial migration in response to chemoattractants such as hepoxilin A3 (HXA3), N-Formylmethionyl-leucyl-phenylalanine (fMLP) and CXCL8/IL-8 (PubMed:25486861). Required for neutrophil transepithelial migration in response to S.typhimurium infection (PubMed:25486861). May act as a positive regulator of endothelial cell apoptosis in response to blood flow-derived shear stress (By similarity). {ECO:0000250|UniProtKB:E9QHT9, ECO:0000250|UniProtKB:Q9JK95, ECO:0000269|PubMed:25486861}. This is the function of Ensembl gene identifier ENSG00000112378 (PERP, p53 apoptosis effector related to PMP22).