Upon primary infection, naïve CD8+ T cells (TN) are activated by antigen‐presenting cells, clonally expand, and differentiate into multiple subsets, including memory CD8+ T cells, namely, central memory T cells (TCM) and effector memory T cells (TEM) (Sallusto et al., 1999; Williams & Bevan, 2007). Here, CD8A is linked to infection.