CD4 and hepatocellular carcinoma: Nanoliposomal C6-ceramide (LipC6) not only induces apoptosis and prevents HCC-induced immune tolerance in HCC cells, it also significantly decelerates the growth of liver cancer cells, enhances tumor-infiltrating CD8+ T cells, and inhibits tumor-resident CD4+ CD25+ forkhead box protein P3 (FoxP3+) Treg cells in combination with anti-CTLA4 Ab (102).