RBP3 (retinol binding protein 3), also known as IRBP (interstitial retinol binding protein), is a photoreceptor-derived protein that shuttles 11-cis and all-trans retinoids between the retinal pigment epithelium and photoreceptor cells, playing a critical role in visual pigment regeneration and retinal homeostasis 1. Beyond its canonical retinoid transport function, RBP3 has emerged as a multifunctional retinal protein with neuroprotective and anti-inflammatory properties 2. RBP3 is genetically associated with corneal curvature and axial length in Asian populations, with a missense variant (rs11204213) showing significant effects on both parameters 3. Pathologically, RBP3 mutations cause RBP3-associated retinopathy, characterized by early-onset high myopia, progressive retinal dystrophy, and both rod and cone photoreceptor dysfunction, with slow progression over decades 4. Additionally, RBP3 mutations are implicated in retinitis pigmentosa 66. Recently, RBP3 has been identified as a potential biomarker for diabetic retinopathy; recombinant RBP3 therapy normalized retinal vascular and neural dysfunctions and reduced inflammatory cytokines in diabetic models more comprehensively than anti-VEGF treatment alone 2, while reduced RBP3 levels in extracellular vesicles correlate with proliferative diabetic retinopathy progression 5. RBP3 regulation via the YY1/RBP3 axis has also been implicated in psoriasis pathogenesis 6.