CSF3 and infection: Human granulocyte-colony stimulating factor (G-CSF) is a haematopoietic glycoprotein produced by stromal cells, macrophages, endothelial cells, fibroblasts and monocytes which binds with high affinity to the G-CSF receptor expressed on neutrophilic precursor cells in the bone-marrow, inducing them to proliferate and differentiate into infection-fighting neutrophils without significant haemopoietic effects on other lineages of blood cells.