“…The tumor microenvironment is a complex and heterogeneous ecological environment, consisting of cancer cells, stromal cells, blood vessels, and extracellular matrix, which affect cell proliferation, mutation, invasion, metastasis, and drug treatment efficacy. [6][7][8] Several studies have found significant heterogeneity between primary NSCLC and its paired metastatic microenvironment, such as the immune environment, angiogenesis, and biomarkers. 9-13 Moreover, different gene expression profiles were noted between primary lesions and paired metastases in patients with NSCLC, such as EGFR, KRAS, and other molecular expressions, including VEGFR, ERCC1, and KI67.…”