CD8A and viral infectious disease: Over-expression of survivin, a downstream molecule of c-Myc, or CA-IKKβ, a downstream molecule of NF-κB that compensates for the deficiency of Nfkb1 in canonical NF-κB activity [17], substantially reversed the defective development of memory CD8+ T cells in the absence of CD28 or OX40 during viral infection (figures 3, –5).