NPHP1 and cyst: Previous immortal cell models are easy to manipulate and to examine the molecular mechanisms related to NPHP1 (Garcia-Gonzalo et al., 2011; Sang et al., 2011; Chaki et al., 2012; Gupta et al., 2015; Shi et al., 2017); however, it is hard to recapitulate the complex tissue organization and degeneration, such as nephrogenesis and cyst formation in kidneys.