PIK3R4 and cystic kidney disease: VPS15 localizes to cilia (basal bodies and axonemes) [22] and fibroblasts from patients with a mutation in the VPS15 gene displaying a ciliopathy phenotype (retinitis pigmentosa, limb abnormalities and renal cysts) show shorter cilia, because of defective formation and/or release of IFT20 positive vesicles from the cis-Golgi [44].