OCRL and oculocerebrorenal syndrome: Cilia play a major role in sensing and transducing chemical and mechanical cues, and it has been reported that the lack of OCRL leads to an increase in PtdIns(4,5)P2 levels at the transition zone of cilia causing reduced accumulation of sonic hedgehog protein upon stimulation with a hedgehog agonist [22]; however, the role and contribution of cilia defects to the Lowe syndrome phenotype are unclear.