This gene encodes a member of the peptidase S1 family of serine proteases. Alternative splicing results in multiple transcript variants, at least one of which encodes a preproprotein that is proteolytically processed to generate a chymotrypsin-like protease. This protein is reported to be constitutively expressed in the NK (natural killer) cells of the immune system and may play a role in the cytotoxic arm of the innate immune response by inducing target cell death and by directly cleaving substrates in pathogen-infected cells. This gene is present in a gene cluster with another member of the granzyme subfamily on chromosome 14.