KLK12 (kallikrein related peptidase 12) is a serine protease that functions primarily in extracellular matrix remodeling and cellular regulation. The enzyme efficiently cleaves extracellular matrix proteins including fibronectin and tenascin, generating fragments that regulate endothelial cell adhesion and migration 1. KLK12's proteolytic activity antagonizes fibronectin polymerization and promotes endothelial cell migration, contributing to angiogenesis 1. The protein exhibits differential expression patterns across cancer types, being overexpressed in colorectal cancer where it promotes cell viability, migration, and invasion through AMPK and mTOR signaling pathways 2. Conversely, KLK12 expression is downregulated in breast cancer tissues, with the KLK12sv3 splice variant serving as a favorable prognostic marker associated with lower tumor grade and longer disease-free survival 3 4. In infectious disease contexts, KLK12 regulates matrix metalloproteinases (MMP-1 and MMP-9) via bradykinin receptors in tuberculosis, serving as a diagnostic biomarker for differentiating latent and active disease states 5. Additionally, KLK12 plays a role in pancreatic endocrine progenitor cell motility during development 6. The gene undergoes alternative splicing, producing multiple variants with distinct expression patterns and potential clinical significance 7.