PDCD1 and hepatocellular carcinoma: These analyses, which were stratified by different immunotherapy regimens involving CTLA4 and/or PD1/PD-L1 blockers, revealed that patients with high ORAOV1 expression had significantly lower IPS across regimens targeting CTLA4 and/or PD1/PD-L1 (p < 0.05), suggesting that ORAOV1 overexpression may be associated with reduced response to immune checkpoint inhibitors in HCC (Fig. 5C).