In a previous study, TUNEL staining of fragmented DNA showed that large numbers of PBMC (mostly CD8+ T lymphocytes) were undergoing apoptosis around the time of defervescence in DENV-1- or DENV-3-infected Thai children [69], and the degree of apoptosis correlated with disease severity and with the risk of DHF. The gene discussed is CD8A; the disease is Dengue hemorrhagic fever.