We observed that inactivation of the Pkd1 gene generated a truncated tagged protein lacking the C-terminal domain (Figures 1D and E) and resulting in a phenotype very similar to the one described for all other knock-out lines, including oedema, haemorrhage, and cystic kidneys (Figure S2) by day E15.5 [2]–[6], [40]. The gene discussed is PKD1; the disease is Renal cyst.