CD8A and infection: For example, studies have provided evidence that the CD8+ T cell response is associated with controlling (1) infections by intracellular bacteria, such as Mycobacterium tuberculosis [2,3,4,5], Salmonella typhimurium [6,7], and Listeria monocytogenes [8], (2) infections by intracellular viruses, such as herpes simplex virus type 1 [9,10,11], hepatitis B virus [12,13], and respiratory syncytial virus [14,15], and (3) intracellular infections by protozoa such as Plasmodium [16,17,18,19], Toxoplasma gondii [20], and Trypanosoma cruzi [21].