Whole cell lysates from mice SI figure 1: knockdown efficiency and inhibitor efficiency and selectivity, and isotype controls B A Non-target RNAi + + - - STAT5 inhibitor 0 0 100 200 (μg/ml) Gene specific RNAi - - + + IFN-α - + + + (20μg/ml) pYSTAT5 STAT1 Total STAT5 β-actin b-actin pYSTAT3 STAT3 Total STAT3 β-actin b-actin pYSTAT1 STAT5 Total STAT1 b-actin β-actin C Non-target RNAi STAT5 RNAi C’ F1 Pkd1 WT F1 Pkd1-/- 3% 1.4% FSC F1 Pkd1-/- P(ser10) H3 D Whole cell lysates from mice pY STAT5 PCNA IgG b-actin Control Pkd1 fl/fl 11 wks 16 wks Pkd1 KO