MDK and posterior cortical atrophy: The combination of proteomic and transcriptomic analysis as well as functional assays revealed several new KLK14 substrates (agrin, desmoglein 2, vitronectin, laminins) and KLK14‐regulated genes (Interleukin 32, midkine, SRY‐Box 9), particularly an involvement of the mitogen‐activated protein kinase 1 and interleukin 1 receptor pathways, and an involvement of KLK14 in the regulation of cellular migration, supporting its involvement in aggressive features of PCa progression.