CD4 and hepatocellular carcinoma: Research by Zhou ZJ et al. [86] illustrated that the high infiltration level of plasmacytoid DCs is related to the poor prognosis of HCC, and plasmacytoid DC infiltration in HCC can promote tumour progression by promoting the immunosuppression of CD4+ type 1 T regulatory (Tr1) cells [87], which is basically consistent with our research conclusions.