IL4 and infection: However, the central dogma of Th1 and Th2 cells and their signature cytokines, INF gamma and IL-4/IL-13 related to resistance or susceptibility to infection is changing toward interconnected pathways in which depending on the disease model, the IL-4 and even the IL-13 can mediate Th1 immunity (Hurdayal and Brombacher, 2014).