Background：

This gene product is a member of a group of related serine proteases from the cytoplasmic granules of cytotoxic lymphocytes. Cytolytic T lymphocytes (CTL) and natural killer (NK) cells share the remarkable ability to recognize; bind; and lyse specific target cells. They are thought to protect their host by lysing cells bearing on their surface ‘nonself‘ antigens; usually peptides or proteins resulting from infection by intracellular pathogens. The protein described here lacks consensus sequences for N-glycosylation present in other granzymes.