KLK11

Kallikrein-related peptidase 11 (KLK11) is a secreted serine protease involved in proteolytic cascades and tissue homeostasis^[1][2]. KLK11 participates in skin desquamation by degrading corneodesmosomes, a process essential for normal stratum corneum shedding^[3][4]. Mechanistically, KLK11 activation occurs downstream of other kallikreins such as KLK8, forming a regulated proteolytic network^[5]. KLK11 exhibits multiple mRNA splice variants that are differentially expressed across normal and cancerous tissues, suggesting isoform-specific functions^[6][7]. Compared with KLK10 and other KLK family members, KLK11 shows unique signal peptide processing, subcellular localization, and extracellular secretion, which affect its enzymatic activity^[3][8]. In disease models, KLK11 is associated with malignancies including triple-negative breast cancer, ovarian cancer, and gastric cancer, where expression levels correlate with prognosis or tumor progression^{[2][9][10][11]}. KLK11 also shows altered expression in dermatological conditions such as psoriasis and autosomal-dominant cornification disorders, emphasizing its relevance in epidermal physiology and pathology^{[3][4][12][13]}. Functional studies indicate that KLK11 enzymatic activity can be modulated by zymogen activation, post-translational modifications, and interactions with other KLKs, enabling experimental applications for biomarker evaluation and therapeutic targeting^[1][5][9]. These features distinguish KLK11 from closely related isoforms and provide a basis for designing isoform-specific assays or inhibitor studies^[6][7][10].