Mechanistically, TIM4 on the surface of cavity-resident macrophages interacts with its receptor phosphatidylserine (PS) upregulated on the surface of activated cytotoxic CD8+ T cells, which leads to CD8+ T cells sequestrated away from tumor targets and proliferation suppression by TIM4+ macrophages (Chow et al., 2021). The gene discussed is TIMD4; the disease is neoplasm.