By contrast, neutrophils in the TME in Smad3-KO mice contained a low proportion of N2 and a high proportion of N1 phenotype cells (Fig. 2D, E and Supplementary Fig. 2C, D), implying a role for Smad3 in the N1/N2 polarization of TAN in lung cancer. This evidence concerns the gene SMAD3 and lung carcinoma.