To evaluate the antitumor effect of KLK inhibition, cell proliferation was assessed in the following PCa cell lines after treatment with different concentrations of MDPK67b at different time points (days 1, 3, 5, and 7): LNCaP (androgen‐sensitive), C4‐2 (AR‐positive cell line growing without androgens but still responding to androgen levels), and DU145 (androgen‐insensitive). This evidence concerns the gene AR and posterior cortical atrophy.