qPCR and WB detected the expression of TCF21 and Notch4 mRNAs and proteins in the cells of each group, implying that as compared with the normal cell BEAS-2B, the expression of TCF21 in lung cancer cell A549 was substantially increased, while Notch4 was markedly decreased; moreover, the expression of both TCF21 and Notch4 were markedly decreased in the TAM group compared with the M group (Figure 2). This evidence concerns the gene TCF21 and lung cancer.