Our data indicate that overexpression of HIPK2KD and treatment of BT173 reduced the renal fibrosis to a similar extent in mice with FAN, and that administration of BT173 in Pax8-HIPK2KD mice did not provide additional benefit, suggesting that both HIPK2 activity and its interaction with Smad3 are required for its profibrosis effect. This evidence concerns the gene SMAD3 and renal fibrosis.