The protein encoded by this gene is a mitochondrial acyl-CoA thioesterase of unknown function. Two transcript variants encoding different isoforms have been found for this gene. Acyl-CoA thioesterases are a group of enzymes that catalyze the hydrolysis of acyl-CoAs to the free fatty acid and coenzyme A (CoASH), providing the potential to regulate intracellular levels of acyl-CoAs, free fatty acids and CoASH. Active on long chain acyl-CoAs.