CD8A and hepatocellular carcinoma: Some risk factors like HBV may result in a unique microenvironment that favors the distinct microbiota colonization, which increases the recruitment and infiltration of CD8 + T cells, monocytic MDSCs (mMDSCs) and polymorphonuclear MDSCs (pmnMDSCs) in HBV-HCC, and finally accelerated the disease progression via inhibiting host antitumor immunity [165].