RDH11 is a retinol dehydrogenase that catalyzes NADP-dependent oxidation of retinoids, displaying high activity toward 9-cis, 11-cis, and all-trans-retinol 1. It functions as a dual-substrate enzyme with C15 pro-R specificity, uniquely metabolizing both cis- and trans-retinols 1. In the retinal pigment epithelium, RDH11 plays an auxiliary role in visual pigment regeneration by complementing RDH5 in converting 11-cis-retinol to 11-cis-retinal; mice lacking RDH11 exhibit delayed dark adaptation following intense light exposure 2. RDH11 can also reduce lipid peroxidation products in vitro, though RDH12 appears more physiologically relevant for 4-hydroxynonenal detoxification in photoreceptors 3. Beyond retinoid metabolism, RDH11 regulates hepatic cholesterol homeostasis by dampening cellular stress associated with cholesterol synthesis; it is downregulated during high-cholesterol diet and upregulated by statins in a SREBP2-dependent manner 4. RDH11 mutations cause syndromic retinal dystrophy with juvenile cataracts, intellectual disability, and myopathy, with disease-associated protein mislocalization observed in muscle tissue 5. Additionally, RDH11 can be hijacked as a bioactivation enzyme for alkynylcarbinol prodrugs, generating protein-reactive electrophiles useful for therapeutic applications 6.