IFNG and malaria: However, IFN-γ is not only produced by T-bet+ Th1 cells but also by NK cells, NKT cells, and γδ T-cells (37, 38) as well as CD8+ T-cells, and it is not always clear whether Th1 cells, IFN-γ, or IFN-γ from Th1 cells per se are the main players in early protection or pathology in experimental malaria.