Then, effector CD8 T cells recognize class I MHC-peptide (pMHC I) complexes on specific target cells in the periphery and ultimately induce the destruction of target cells.During acute viral infection, the majority of effector CD8 T cells die by means of apoptosis after antigen clearance; only ~5–10% of the cells survive and differentiate into memory CD8 T cells to establish long-term immune protection (2). The gene discussed is CD8A; the disease is viral infectious disease.