CD8A and cancer: An oncolytic herpes simplex virus, which encodes the fundamental anti-tumor cytokine, interleukin 12 (IL-12), (designated G471-mIL12), can selectively kill cancer cells while inducing anti-tumor immunity (83), which is mainly manifested by the upregulation of CD8+ T cells activation markers in tumor microenvironment and the inhibition of tumor angiogenesis (84).