HLA-A and viral infectious disease: In the case of viral infections, classical HLA Class I (HLA-A, -B, and -C) molecules on the surfaces of infected cells present virus-derived peptides to CD8+ cytotoxic T lymphocytes, leading to their elimination by the latter, whereas classical HLA Class II (HLA-DR, HLA-DP, and HLA-DQ) molecules display such degradation products for stimulation of CD4+ helper T lymphocytes, generating production of neutralizing antibodies and inflammatory cytokines (6).