KCTD1 and renal fibrosis: Consistent with β-catenin hyperactivation being profibrotic and leading to renal fibrosis in mice lacking KCTD1 activity, kidneys of aged Aqp2Cre+Tfap2afl/fl mice that had no significant increase in active β-catenin levels did also not develop renal fibrosis (Supplementary Fig. 6c).