TGFB1 and pulmonary fibrosis: There was no difference in the cell cycle and proliferation of MRC5 and HLF5 transfected with P27 siRNA plus Rictor siRNA or P27 ovexpression vector plus Rictor siRNA (Figure 5), which revealed that the role of P27 in TGF-β-induced pulmonary fibrosis was controlled by MTORC2.