Although increased neutrophils have already been described in patients with many types of tumors including GC [20], to our knowledge, this is the first demonstration of a statistically significant correlation between prevalently high B7-H4-expressing neutrophils in human tumors and poor prognosis; it is also the first demonstration for tumor-derived GM-CSF to induce B7-H4 on neutrophils within the tumor environment. The gene discussed is CSF2; the disease is gastric cancer.