Immunosuppressive cells, such as the increase in Tregs in peripheral blood and tumor-infiltrating lymphocytes (TILs) in patients with liver cancer, can promote transforming growth factor-β (TGF-β) or increase the inhibitory regulatory molecules CTLA4 and PD-L1, further inhibiting the immune response [23,24]. The gene discussed is CTLA4; the disease is neoplasm.