CD4 and hepatocellular carcinoma: Nada Chaoul et al. used flow cytometry to analyze HCC tumors, peritumor tissue, and peripheral blood mononuclear cells from 14 patients and found that, compared to the peritumor region, the recruitment of cytotoxic cells including CD4+ and CD8+T cells in the tumor itself was impaired; in contrast, the effector memory CD4+T cells were more attracted to HCC tissue.