PDE5 expression has also been identified in several cancer types such as colon adenocarcinoma, esophageal, bladder squamous carcinoma, metastatic breast, pancreatic, glioblastoma, lung, and prostate (PCa) cancers as compared to adjacent normal tissues [4, 9–14] as well as in many cancer cells lines, including PCa cell lines LNCaP and PC3 [15]. Here, PDE5A is linked to cancer.