IFT140 and autosomal dominant polycystic kidney disease: The monoallelic variants were specific in NEK8 (i.e., p.R45W) [21, 22] and in NPHS2 (p.L330Vfs*15 with a premature stop in the last exon) [24], suggesting a dominant negative effect [21], but the IFT140 variants in mild ADPKD are intriguingly loss-of-function variants [23].