CRALBP, which stands for Cellular Retinaldehyde-Binding Protein, is a protein that plays a critical role in the visual cycle, particularly in the regeneration of 11-cis-retinal for use in rod visual pigments such as opsin and rhodopsin. It is expressed in the retinal pigment epithelium (RPE) and Müller glia (MG) and is essential for maintaining visual function. CRALBP binds to 11-cis-retinol in the visual cycle, thereby augmenting the activity of retinoid isomerohydrolase RPE65 and facilitating the oxidation of 11-cis-retinol to 11-cis-retinal. This process is vital for the photoisomerization of 11-cis-retinal to all-trans-retinal, which is a key step in the visual cycle. In terms of therapeutic implications, gene therapy targeting the RLBP1 gene, which encodes CRALBP, has shown promise in preclinical studies. For instance, gene therapy with adeno-associated viral (AAV) vectors expressing a corrected RLBP1 gene (AAV8-RLBP1) has been shown to restore CRALBP levels and improve dark adaptation in Rlbp1-deficient mice. This suggests potential for treating retinal dystrophies associated with CRALBP dysfunction.