IL4 and brucellosis: The serum levels of IFN‐γ and TNF‐α increased in the brucellosis group compared with the controls, and a significant reduction was observed after treatment, but the serum level of IL‐4 was not significantly different between the control and patient groups and also after treatment.(13) Furthermore, Reza et al studied IFN‐γ and IL‐4 levels in patients with brucellosis before and after treatment in Iran.