alpha-methylacyl-CoA racemase(AMACR/P504S) is Prostate-specific antigen (PSA) screening for prostate cancer is now widespread in the United States among men of all ages. However PSA has limited specificity because benign disease, including prostatic enlargement and inflammation, can increase PSA levels. Thus, a more specific prostate cancer markers is needed. One such potential marker is AMACR, an enzyme that is involved in peroxisomal beta-oxidation of dietary branched-chain fatty acids. Recent studies have shown that, compared with expression in normal or benign prostate epithelium, AMACR is consistently overexpressed in prostate cancer epithelium, making it a specific marker for cancer cells within the prostate gland. Furthermore, overexpression of AMACR may increase the risk of prostate cancer because its expression is increased in premalignant lesions (prostatic intraepithelial neoplasia).