While these cells are present in many tissues under normal physiological conditions, a marked accumulation of the CD8+ CD103+ αβ T cell subset is often associated with localized immune phenomena in epithelial and neuronal compartments, including graft rejection (Hadley et al., 1999; Wong et al., 2003), chronic inflammation (Ebert et al., 1998), infection (Piet et al., 2011), tumor development (Ling et al., 2007; Masson et al., 2007; Webb et al., 2010), and autoimmune processes (Pauls et al., 2001; Mizukawa et al., 2002; Teraki and Shiohara, 2002). Here, CD8A is linked to infection.