TGFB1 and idiopathic pulmonary fibrosis: Furthermore, we recently found that the TGF-β1-induced active form of β-catenin was inhibited in siRNA-MUC1 A549 and MRC5 cells, thus suggesting that Thr41 (1224) and Tyr46 (1229) MUC1-CT phosphorylations are needed to increase active-β-catenin in ATII cells and lung fibroblasts from IPF patients [19].