The importance of CD8α DCs and NK cells was revealed from experiments conducted in mice lacking CCR5, IRF8, or basic leucine zipper transcription factor ATF-like 3 (BATF3), a transcription factor required for the development of CD8α DCs, as all of them succumb quickly to the infection (Scharton-Kersten et al., 1997; Khan et al., 2006; Mashayekhi et al., 2011). The gene discussed is CD8A; the disease is infection.