PTGR1 (prostaglandin reductase 1) is a NAD(P)H-dependent oxidoreductase that catalyzes metabolic inactivation of pro- and anti-inflammatory eicosanoids 1. The enzyme efficiently reduces the 13,14 double bond of 15-oxoprostaglandins (15-oxo-PGE1, 15-oxo-PGE2, 15-oxo-PGF1-α, and 15-oxo-PGF2-α) and catalyzes leukotriene B4 oxidation to less active 12-oxo-LTB4 metabolites 1. PTGR1 also metabolizes α,β-unsaturated alkenals and ketones, particularly medium-chain compounds, and may inactivate the cytotoxic lipid 4-hydroxy-2-nonenal 1. Beyond eicosanoid metabolism, PTGR1 expression is dysregulated in multiple cancers. NRF2-mediated upregulation of PTGR1 in hepatocellular carcinoma promotes cell proliferation and resistance to oxidative stress 2. In prostate cancer, PTGR1 overexpression via super-enhancer activation drives metformin resistance through cell cycle acceleration 3. PTGR1 also participates in cell proliferation in thoracic ossification of the ligamentum flavum via JNK pathway activation 4. Clinically, PTGR1 serves as a critical biomarker and therapeutic target: it is essential for activating acylfulvene anticancer agents in urothelial carcinoma 5, and human PTGR1 upregulation enhances hydroxymethylacylfulvene efficacy 2-10 fold in cancer cells 6.