Aberrant expression of p63 may be seen in rare cases of prostate cancer. The image shows immunostaining with PIN4 cocktail (CK5/14, p63, AMACR). The smaller glands are clearly infiltrating in between larger benign glands which show a continuous basal cell layer. p63 staining in the smaller glands is within the tumor cells and not in a basal cell distribution. Both the cancer glands as well as the benign glands show racemase positivity (red chromogen).