Therefore, latent infection is thought to reflect a critical balance between Th1 and Th17 responses that serve to control the pathogen and Th2 cells, regulatory T cells and immunoregulatory cytokines (e.g.,IL-10 and TGFβ) that limit immune-mediated pathology [9]. This evidence concerns the gene TGFB1 and disease arising from reactivation of latent virus.