Pro-tumorigenic neutrophils have been shown to directly promote tumor growth via cytokine secretion (e.g., TNF-α (by binding to TNFR2), IL-6 and IL-17) and ROS production (thereby increasing mutagenesis); form NETs; recruit tumor-supporting cells into the TME; promote angiogenesis; and induce tumor cell motility, migration and invasion (Figure 5) [121,127,128,129]. The gene discussed is IL17A; the disease is neoplasm.