In addition, the immune microenvironment of HCC provides a suitable growth environment for tumor development (13), and chimeric antigen receptor (CAR) T-cell therapies and monoclonal antibodies against programmed cell death protein 1 (PD-1), thus improving the prognosis of patients with HCC by altering the pathways where immune cell checkpoints are located and thus improve the prognosis of patients with HCC (14). Here, PDCD1 is linked to neoplasm.