KLK7

KLK7 (kallikrein-related peptidase 7) is a chymotrypsin-like serine protease that functions as a major regulator of epidermal desquamation and skin barrier homeostasis through proteolytic processing of corneodesmosomal components in the stratum corneum^[1][2]. Mechanistically, KLK7 participates in the epidermal kallikrein protease network that controls corneocyte shedding, and dysregulated KLK activity alters stratum corneum integrity, leading to impaired barrier function and inflammatory skin phenotypes^[2][3]. In disease settings, elevated or excessive KLK7 activity has been linked to disorders characterized by abnormal desquamation and inflammation, including atopic dermatitis, psoriasis, and Netherton syndrome, highlighting its importance in epidermal pathophysiology^[3][4]. Experimental studies further demonstrated that KLK7 promotes atopic dermatitis-associated chronic itch through an epidermal-neural mechanism that is separable from cutaneous inflammation, supporting its value as a mechanistic target in disease models^[4]. Compared with related epidermal kallikreins such as KLK5 and KLK14, KLK7 exhibits chymotrypsin-like substrate specificity and represents the most abundant KLK protease in the stratum corneum, providing a distinct functional profile within the epidermal protease cascade^[5]. For experimental applications, highly selective KLK7 substrates and inhibitors have been developed and used to dissect KLK-specific proteolytic activity, enabling mechanistic studies of desquamation and skin barrier regulation with improved isoform selectivity^[5].