Receptor for granulocyte colony-stimulating factor (CSF3), essential for granulocytic maturation. Plays a crucial role in the proliferation, differientation and survival of cells along the neutrophilic lineage. In addition it may function in some adhesion or recognition events at the cell surface. Mutations in CSF3R acquired in multipotent hematopoietic progenitor cells and resulting in truncated hyper-responsive forms of the receptor, have been identified in most cases of severe congenital neutropenia (SCN). Patients carrying these mutations are at risk for developing myelodysplastic syndromes and/or acute myeloid leukemia. Constitutive mutations leading to hyporesponsive forms of the receptor are responsible for the refractoriness to CSF3 treatment observed in some SCN patients.