Additionally, GPR84 is involved in immune regulation as its expression has been described predominantly in immune cells.176 A study proved that GPR84 enhanced macrophage phagocytosis of adipocyte plasma membrane-associated protein (APMAP)-deficient cancer cells.177 This means that CPR84 may be a key point linking the tumor metabolic microenvironment with anti-tumor immunity. This evidence concerns the gene APMAP and neoplasm.