Serine protease inhibitor, probably important for the anti-inflammatory and/or antimicrobial protection of mucous epithelia. Contribute to the integrity and protective barrier function of the skin by regulating the activity of defense-activating and desquamation-involved proteases. Inhibits KLK5, it's major target, in a pH-dependent manner. Inhibits KLK7, KLK14 CASP14, and trypsin. Highly expressed in the thymus and stratum corneum. Also found in the oral mucosa, parathyroid gland, Bartholin's glands, tonsils, and vaginal epithelium. Very low levels are detected in lung, kidney, and prostate. Contains at least one active inhibitory domain for trypsin (domain 6). Proteolytically processed by furin in individual domains (D1, D5, D6, D8 through D11, and D9 through D15) exhibiting various inhibitory potentials for multiple proteases. The disease is caused by variants affecting the gene represented in this entry. SPINK5 mutation db