CD8A and hepatocellular carcinoma: Kim et al subsequently identified two subgroups of HCCs: the first group with a discrete population of PD-1high CD8+ T-cells was more aggressive, and the second group without a discrete population of PD-1high CD8+ T-cells was much less aggressive; the first HCC group had higher levels of predictive biomarkers of response to anti-PD-1 therapy, and incubation of the T cells from these HCCs with antibodies against PD-1, TIM3 or LAG3 restored proliferation and production of IFNγ and TNF in response to anti-CD3 treatment [17, 18].