One noteworthy difference from the report of Sheehan et al. (Sheehan et al., 2007), Landers et al.’s immunohistochemical analysis of claudin-4 was supported by a comparative evaluation of α-Methylacyl-CoA racemase (AMACR) and prostate-specific membrane antigen (PSMA)—two well-established prostate cancer markers (Landers et al., 2008). Here, CLDN4 is linked to Familial prostate cancer.