The antigen-specific mCD4+ T cells clustered in areas associated with interferon gamma (IFN-γ), tumor necrosis factor (TNF), and interleukin-2 (IL-2) expression, which are the signature cytokines of the type 1 T helper (TH1) cells typically induced during viral infections (Figures 3C and 3D). Here, PIGN is linked to viral infectious disease.