ACOX3 and neoplasm: The expression of sterol carrier protein X (SCPx), which is obligatory for the peroxisomal thiolytic breakdown of branched-chain fatty acids and bile acid intermediates [29], is clearly increased in both tumor cells, suggesting, along with the increases in ACOX3 and AMACR [18], that branched-chain fatty acids metabolism may play an important role in PCa cells.