Consistent with chronic viral infection resulting in diminished Th1 differentiation and function (Fuller et al., 2004; Brooks et al., 2005; Fahey et al., 2011; Yamada et al., 2016), our integrated scRNA-seq analysis demonstrated that the proportions of both Ly6c-hi and Lag3-hi Th1 cells were dramatically reduced during chronic vs acute LCMV infection. This evidence concerns the gene LAG3 and viral infectious disease.