However, it seems likely that continuous low-level IFN production during the chronic stage of infection is likely to be detrimental to the host and contribute to disease (Figure 3), for example by promoting TRAIL-mediated bystander apoptosis of CD4 T cells (Barblu et al., 2012; Hardy et al., 2007; Stary et al., 2009). Here, IFNA1 is linked to infection.