The function of RRH (retinal pigment epithelium-derived rhodopsin homolog, Ensembl gene identifier ENSG00000180245) is as follows. Opsin-family protein localized to the apical microvilli of the retinal pigment epithelium (RPE), where it may participate in retinoid exchange between photoreceptors and RPE or light-dependent retinoid processing. Although it possesses the structural features of a GPCR, no evidence for canonical G protein activation in vivo has been reported. .