PKD1 and cystic kidney disease: While perinatal inactivation of Pkd1 in this genetic background produces a rapid and severe model of kidney cystogenesis and functional decline over a compressed timeline, inactivation of Pkd1 at PND18 induces an adult-onset, slowly progressing model of cystic kidney disease which leads to renal failure over the course of several months, and offers the opportunity to evaluate treatment strategies over a chronic time window (Leeuwen et al., 2007; Leonhard et al., 2016).