Since POSTN+ CAFs (C02_POSTN and C07_MKI67) might be closely related to the pro‐invasive and immunosuppressive TME, we confirmed the co‐expression of key markers, including periostin (POSTN), COL11A1 and αSMA (ACTA2) by immunohistochemistry (IHC) staining (Figure S5) on two formalin‐fixed paraffin‐embedded (FFPE) NSCLC samples. The gene discussed is ACTA1; the disease is non-small cell lung carcinoma.