(A) PTHLH expression in SCP2 cells treated with inhibitors of various pathways (n = 3). (B) shRNA-mediated SMAD4 KD (shSMAD4) in SCP2 cells. (C) PTHLH expression in SCP2 cells with SMAD4 KD (n = 3). (D) TGF-β activation of RHOA in SCP2 cells. (E) SMAD3 linker (Ser204, Ser208) and C-tail (Ser425) phosphorylation in SCP2 cells affected by TGF-β, C3, and DLC1. (F) PTHLH promoter activities in SCP2 cells affected by TGF-β, DLC1 OE, SMAD4 KD, and WT and mutant SMAD3 (n = 4). (G) ChIP-qPCR analyses of SMAD3 binding on PTHLH promoter in SCP2 cells (n = 3). (H) ChIP analyses of SMAD3 binding on PTHLH and IL11 promoters in SCP2 cells. **P < 0.01 vs. TGF-β–untreated control.