GM-CSF and IL-3 promote emergency myelopoiesis (i.e., generation and differentiation of myeloid cells upon infection or in the context of inflammation) [9,11,12] and also modulate effector functions of several innate immune cell subsets in vitro and in vivo [1,13,14,15,16,17,18,19,20,21]. This evidence concerns the gene IL3 and infection.