Anti-Rhodopsin antibodies detect the protein encoded by the gene RHO in humans. The protein may also be known as RH1, CSNBAD1, OPN2, RP4, opsin 2, rod pigment, and opsin-2. The reported amino acid length is 348 and the expected mass is 38.9 kDa. Variants of this antigen may also be found in other species, including E. coli, fly, canine, porcine, monkey, mouse, and rat.