Kallikreins-related peptidases (KLKs) are proteases that are important for the desquamation process of the skin (cell shedding). Kallikreins are also associated with carcinogenesis and some serve as a novel cancer and other disease biomarkers. Kallikrein-13/KLK13 is important in lung cancer by allowing lung adenocarcinoma spreading through promoting the expression of various adhesion molecules and it in assisting in extracellular matrix protein degradation necessary for movement. Kallikrein-13/KLK13 also plays a role in salivary tumors and ovarian cancer as well as other cancers in a similar fashion. In both normal and cancerous tissues, Kallikrein-13/KLK13 is secreted into the ECM and expressed in many tissues in both the embryo and adult.