Periphilin, known as PPHLN1 or gastric cancer antigen Ga50, plays a role in epithelial differentiation and contributes to epidermal integrity and barrier formation. It interacts with periplakin, a known precursor of the cornified cell envelope. Periphilin 1 is ubiquitously expressed and localizes to nucleus and cytoplasm. Existing as eight alternatively spliced isoforms, Periphilin is highly insoluble and contains a putative nuclear localization signal (NLS) within its N-terminal half, a prerequisite for the formation of insoluble complexes and a possible caspase recognition sequence and a potential nuclear export signal. Periphilin may play an important role in the nervous system.Synonyms: Ga50, Gastric cancer antigen Ga50, HSPC206, HSPC232, PPHLN1, Periphilin-1