Involved in the positive regulation of starvation-induced autophagy (PubMed:25076851). Secreted in a non-classical form. A signal peptide sequence at position 1-31 is predicted. Widely expressed. Highly expressed in the pancreas. The gene coding for this protein is located in the pseudoautosomal region 1 (PAR1) of X and Y chromosomes. Belongs to the short-chain dehydrogenases/reductases (SDR) family.