KLK4 has been implicated in promoting PCa progression by stimulation of tumor growth and metastasis through induction of cancer‐associated fibroblast phenotypes in prostate stromal cells [16], epithelial to mesenchymal transition‐like characteristics [17], and activation of matrix metalloproteinase‐1 (MMP‐1) [18]. Here, KLK4 is linked to posterior cortical atrophy.