During systemic Escherichia coli infection, stimulation of TLR4 mobilizes CD150+CD48−Lineage−/lowSca1+cKit+ hematopoietic stem cells (HSCs) to the spleen to give rise to neutrophils, which contributes to the host defense (Burberry et al., 2014). The gene discussed is KIT; the disease is escherichia coli infection.