Over the last 20 years, there have been a number of immunohistochemical studies of p16 expression in prostate and PCa.23, 24, 25, 26, 27, 28, 29 A variety of antibodies, staining protocols, and scoring systems have been used and studies range in size from several dozen to more than 9000 cancer cases. Here, CDKN2A is linked to cancer.