Serpin B6

Also designated proteinase inhibitor 6 (PI6), Serpin B6 is an intracellular member of the clade B serpin family expressed in most tissues, with particularly high levels in endocrine pancreas, placenta and immune cells. Its best-characterized target is the neutrophil granule protease cathepsin G, and by neutralizing proteases that leak into the cytoplasm during inflammation it protects cells from protease-driven apoptosis. Unlike secreted serpins, PI6 acts inside the cell, buffering granzyme-type and lysosomal proteolytic insults. Altered expression has been reported in tumors and in islet-related disease contexts, making it a subject of oncology and diabetes research. Recombinant Serpin B6 supports mechanistic studies of intracellular protease control.