INPP5E and Joubert syndrome: Previous studies have reported that the level of the prenylated Inositol Polyphosphate-5-Phosphatase E (INPP5E) is reduced in the cilia of fibroblasts from patients carrying ARL3 variants and presenting with Joubert syndrome [9, 38], suggesting that ARL3 regulates the ciliary membrane localization of INPP5E [9, 22, 39, 40].