Using lung cancer models, others have shown that miR-21 alters the tumor microenvironment by increasing the secretion of the pro-inflammatory cytokines TNF- α and IL-6, through the activation of NF-κB, which decreases the number of CD8+ TIL and promotes the polarization of M2 macrophages [42]. The gene discussed is NFKB1; the disease is neoplasm.