Hydrolyzes bioactive fatty-acid esters of hydroxy-fatty acids (FAHFAs), but not other major classes of lipids (PubMed:27018888). Show a preference for FAHFAs with branching distal from the carboxylate head group of the lipids (PubMed:27018888). 9-hexadecanoyloxy-octadecanoate + H2O = 9-hydroxy-octadecanoate + H(+) + hexadecanoate 12-hexadecanoyloxy-octadecanoate + H2O = 12-hydroxyoctadecanoate + H(+) + hexadecanoate 9-(9Z-hexadecenoyloxy)-octadecanoate + H2O = (9Z)-hexadecenoate + 9-hydroxy-octadecanoate + H(+) 12-(9Z-hexadecenoyloxy)-octadecanoate + H2O = (9Z)-hexadecenoate + 12-hydroxyoctadecanoate + H(+) 13-(9Z-hexadecenoyloxy)-octadecanoate + H2O = (9Z)-hexadecenoate + 13-hydroxy-octadecanoate + H(+) 9-octadecanoyloxy-octadecanoate + H2O = 9-hydroxy-octadecanoate + H(+) + octadecanoate 12-octadecanoyloxy-octadecanoate + H2O = 12-hydroxyoctadecanoate + H(+) + octadecanoate 13-octadecanoyloxy-octadecanoate + H2O = 13-hydroxy-octadecanoate + H(+) + octadecanoate 9-(9Z-octadecenoyloxy)-octadecanoate + H2O = (9Z)-octadecenoate + 9-hydroxy-octadecanoate + H(+) 12-(9Z-octadecenoyloxy)-octadecanoate + H2O = (9Z)-octadecenoate + 12-hydroxyoctadecanoate + H(+) 13-(9Z-octadecenoyloxy)-octadecanoate + H2O = (9Z)-octadecenoate + 13-hydroxy-octadecanoate + H(+) 5-(9Z-hexadecenoyloxy)-octadecanoate + H2O = (9Z)-hexadecenoate + 5-hydroxy-octadecanoate + H(+) Inhibited by N-hydroxyhydantoin carbamate JJH260 and beta-lactone KC01. Highly expressed in heart, ovary, testis, liver, and kidney, at lower levels in spleen, prostate, brain, skeletal muscle, pancreas, small intestine and colon, and undetected in peripheral blood leukocytes, thymus, lung and placenta. AIG1 expression is higher in hair follicles from males than from females. By dihydrotestosterone (DHT). Belongs to the AIG1 family. Extended N-terminus.