SMAD2 and non-small cell lung carcinoma: The invasiveness induced by expressing active PLK1 upregulated the levels of p-Smad2, the TGF-β effector, and the expression of several genes related to TGF-β signaling, including SNAI1, SNAI2, ZEB1, CDH2, IL11, and TNFAIP6. Fourth, the activation of TGF-β signaling through the expression of active PLK1 upregulates TNFAIP6, which promotes metastasis and invasiveness in NSCLC because TNFAIP6 is induced by several growth factors, including TGF-β [30, 31].