Interleukin-3 (IL-3), also known as multi-lineage-colony stimulating factor (Multi-CSF), is a cytokine that supports the growth and differentiation of a broad range of hematopoietic cells types including hematopoietic stem cells, macrophages and lymphoid cells and enhances immune responses during disease and infection (Korpelainen et al. 1996). Here, IL3 is linked to infection.