In mutant specimens, Ndfip2 was primarily localized to large, Lamp1-negative vacuole-like vesicles in primary collecting duct cells cultured from Pkhd1-mutant mice (Supplementary Fig. S4b) and in human ARPKD kidney samples (Fig. 5g). Here, NDFIP2 is linked to autosomal recessive polycystic kidney disease.