CD4 and hepatocellular carcinoma: Due to the highest overexpression in the PD-1 inhibitory molecule on CD4/CD8 T cells in HCC-bearing animals (Fig. 8A, B, Supplementary Fig. S8A, B), we performed a combination therapy comprising α-PD-1 blockade and vaccination with Listeria strains at a very advanced malignant liver disease stage (3.5 weeks after HCC-Ova induction, Supplementary Table S1).