PDCD1 and hepatocellular carcinoma: This inference was subsequently confirmed by in vitro co-culture experiments, which showed that HCCRIN1-sup-CD8 expressed lower levels of PD-1/TIM3 (Fig. 4d, f) and higher levels of IFN-γ/TNF-α/Ki -67 (Fig. 4e, g, Supplementary Fig. 5a), and co-cultured HCC cells tended to be apoptotic (Supplementary Fig. 5b).