Kallikreins are a subgroup of serine proteases containing various physiological functions. kallikreins are involved in carcinogenesis and several have potential as novel cancer and other disease biomarkers. KLK4 is one of the fifteen kallikrein subfamily members localized in a cluster on chromosome 19. In some tissues its expression is hormonally regulated. KLK4 is involved in the degradation of enamel proteins Synonyms: kallikrein-related peptidase 4, EMSP1, KLK-L1, PRSS17, PSTS, Kallikrein-4, Prostase, Kallikrein-like protein 1, Enamel matrix serine proteinase 1, Serine protease 17, EC 3.4.21.