KRT5 and carcinoma: Numerous studies based on the measurement of mRNA and/or protein expression have reported the upregulation of a variety of markers in PCa such as AMACR and AR. Based on several previous immunohistochemistry studies, AMACR is used as a routine tissue biomarker to support the diagnosis of prostate cancer [4, 12, 23, 24] and especially useful for detection of small carcinoma foci in needle biopsies when combined with basal cell marker such as keratin 5/6 or p63 [12].