In the Ksp-cre model, at age 8 days (P8) Pkd1 mutants have highly cystic kidneys but there was no significant difference between the Nnt wild type and mutant strains, though disease severity was more variable in the Nnt wild type background (Fig 7A and S4 Table; n = 10 Nnt mutants and 34 controls). Here, PKD1 is linked to Renal cyst.