Alpha-methylacyl-CoA racemase (AMACR), also known as P504S, is a mitochondrial and peroxisome enzyme. AMACR is expressed in normal liver (hepatocyte), kidney (tubular epithelial cell) and gallbladder (epithelial cell). AMACR is also expressed in Lung (bronchial epithelial cells) and colon (surface epithelium of colon). AMACR is a specific marker of prostate cancer.