PTGR2 belongs to the medium-chain dehydrogenase/reductase superfamily. PTGR2 catalyzes an NADPH-dependent reduction of the conjugated alpha,beta-unsaturated double bond of 15-keto-PGE(2), a key step in terminal inactivation of prostaglandins and suppression of PPARgamma-mediated adipocyte differentiation. Selective inhibition of PTGR2 may contribute to the improvement of insulin sensitivity with fewer side effects.