It has been shown that the protein levels of peroxisomal branched-chain FA β-oxidation enzymes (i.e., α-methylacyl-CoA racemase, peroxisomal multifunctional protein 2) are upregulated in human prostate cancer (Zha et al., 2005) and that this pathway is essential for optimal proliferation of some prostate cancer cell lines (Zha et al., 2003). The gene discussed is HSD17B4; the disease is Familial prostate cancer.