PKD2 and autosomal dominant polycystic kidney disease: However, the cholesterol treatment did not induce the restoration of a lumen-to-spheroid ratio in Pkd2 L515R cells (0.27 ± 0.05, mean ± SD) (Fig 5D), implying that the low abundance of ciliary PC2 caused by the L515R mutation might contribute to the pathogenesis of this mutation in ADPKD, even in the presence of sufficient ciliary cholesterol.