FOXP3 and infection: Indeed, numerous studies showed that infection-associated inflammatory milieu can cause downregulation of Foxp3 expression by Treg cells, impede their suppressor and proliferative capacity, or even confer pro-inflammatory properties, i.e. effector cytokine production; furthermore, pro-inflammatory cytokines, IL-6 and IL-1 in particular, can make effector cells refractory to Treg-mediated suppression14, 16, 18, 19, 49, 50.