Of note, a CRISPR-based screen to identify regulators of Hh signaling detected among many ciliopathy genes few genes mutated exclusively in NPH, not including NPHP1 and NPHP4 or the genes encoding InvsC proteins, suggesting that disrupted Hh signaling plays a less prominent role in isolated NPH than in other ciliopathies (Breslow et al., 2018). Here, NPHP4 is linked to ciliopathy.