Moreover, although recent reports have demonstrated that several transcriptionally distinct CD4+ T cell subsets develop during acute viral infection (Ciucci et al., 2019; Khatun et al., 2021), whether analogous or additional heterogeneous populations of CD4+ T cells emerge during chronic viral infection, and how these subsets compare to those from acute infection have remained significant knowledge gaps in the field. The gene discussed is CD4; the disease is viral infectious disease.