REEP6 and retinitis pigmentosa 1: Receptor expression enhancer protein 6 (REEP6), a member of the REEP/Yop1 family of proteins, influences the structure of the endoplasmic reticulum.158 Arno et al. reported that biallelic mutations in REEP6 cause autosomal-recessive retinitis pigmentosa.159 They identified variants in REEP6 in patients with RP from unrelated families.