This dynamic study of F. gigantica-infected buffalo serum cytokines has revealed that, in the early stages of both primary and secondary infection, Th2/Treg dominated response was induced; this was manifested in increases of IL-4, IL-5, IL-10, IL-13, and TGF-β and reduction of IFN-γ and IL-17. The gene discussed is IL4; the disease is infection.