Following keywords and corresponding Mesh terms, if available, were used: Non-small cell lung cancer, Epidermal growth factor receptor, Tumor micro-environment, Gefitinib resistance, Vasculature, Angiogenesis, Hypoxia, Immune, Fibroblast, Exosome, and Extracellular matrix. The detailed search strategy was demonstrated in the supplement table. The gene discussed is EGFR; the disease is neoplasm.