KLF2 and metastatic malignant neoplasm in the lymph nodes: KLF2 (Kruppel-like factor 2) is a tumor suppressor whose downregulation is related to region 4 hypermethylation in NSCLC tissues, and it is associated with lymph node metastasis and advanced TNM stage, cell viability, cell cycle, inhibition of apoptosis [74], promotion of cell growth, cell survival and proliferation [75], and angiogenesis, improving vascular stability [76], vascular permeability in NSCLC [77], and inflammation, possibly through the regulation of AP-1 [78].