CYP4V2 is a cytochrome P450 monooxygenase localized to the endoplasmic reticulum, primarily expressed in retinal pigment epithelial (RPE) cells, that catalyzes omega-hydroxylation of polyunsaturated fatty acids including docosahexaenoate (DHA) and eicosapentaenoate (EPA), as well as saturated fatty acids such as laurate, myristate, and palmitate 1. The enzyme uses molecular oxygen insertion coupled with NADPH-dependent reduction, facilitating fatty acid metabolism essential for retinal homeostasis and lipid recycling between the RPE and photoreceptors 1. CYP4V2 expression is regulated by peroxisome proliferator-activated receptor gamma (PPARγ), with metabolites including 12-hydroxydodecanoic acid detected in macrophages 2. Biallelic CYP4V2 mutations cause Bietti crystalline corneoretinal dystrophy (BCD), an autosomal recessive chorioretinal degenerative disease characterized by retinal crystalline deposits and progressive RPE, choriocapillaris, and photoreceptor atrophy 1. BCD is particularly prevalent in East Asian populations, with worldwide estimated genetic prevalence of approximately 1:116,000 3. The disease demonstrates accelerated progression with currently limited effective treatments 4. Gene therapy approaches, including AAV-mediated gene augmentation and CRISPR/Cas9-based editing, are in clinical development, with two products advancing to Phase III trials, offering promise for restoring CYP4V2 function and halting disease progression 4, 5.