In particular, neutrophils secreting inflammatory cytokines such as interleukin-2 (IL-2), interleukin-6 (IL-6), interleukin-10 (IL-10), tumor necrosis factor α (TNF-α), and proangiogenic factors including vascular endothelial growth factor (VEGF) provide a favorable tumor microenvironment for cancer progression. The gene discussed is IL2; the disease is cancer.