In addition, phosphatidylserine was identified as an important immune checkpoint that influences immune responses directed against tumor cells and tumor-associated macrophages (TAM) that modulate the tumor microenvironment (TME) and upregulate the expression of TAM receptor tyrosine kinases (Tyro3, Axl, and MerTK) that interact with PS. The gene discussed is AXL; the disease is neoplasm.