Expressed in the basal body and ciliary rootlet of the photoreceptors. Isoform S is detected in most tissues investigated: cortex, liver, kidney, skeletal muscle, adipose tissue, testis, urothelium, lung, bone marrow and retinal pigment epithelium (RPE). Isoform L 2 is widely and abundantly expressed all tissues. Isoform 3 is highly expressed in heart, lung, bone marrow, retina, brain, and RPE. The disease is caused by variants affecting the gene represented in this entry. Belongs to the small GTPase superfamily. Rab family.