CD274 and neoplasm: These include: (i) downregulation of miR-34a, a prerequisite for the synthesis of PD-L1 [102] (ii) activation of NF-kB pathway by PD-L1 [103] (iii) inhibition of HLA expression by viral oncogenic proteins, which results in diminished recognition of tumor cells by the immune system and ineffectiveness of immunotherapy [104] (iv) Similarly, HBVsAg causes cell death in progenitor cells responsible for the production of various types of immune cells which further causes conditions favorable for carcinogenesis [35].