Based on limited published evidence, PTGR3 encodes a 15-oxoprostaglandin 13-reductase that catalyzes reduction of 15-keto-prostaglandins, with highest activity toward 15-keto-PGE2-alpha. The enzyme localizes to mitochondria and peroxisomes. PTGR3 overexpression represses PPARG transcriptional activity and inhibits adipocyte differentiation, suggesting a role in negative regulation of fat cell development. PTGR3 was identified as a co-dependent gene associated with vascular invasion in rectal carcinoma 1, though functional relevance remains unclear. Notably, PTGR3 (ZADH2) is absent from zebrafish peroxisomes despite conservation in mammalian species 2.