Hence, reprogrammed naïve CD8+CTLs producing Th2 cytokines called Tc2s are critical players in Th2 cytokine-associated inflammatory diseases, such as asthma, allergic rhinitis, allergic dermatitis, helminthic infections, and chronic intestinal inflammatory diseases, such as inflammatory bowel disease (IBD) (Figure 3) [211,212,213,214,215]. This evidence concerns the gene CD8A and inflammatory bowel disease.