A human chemotactic polypeptide, DNA (RNA) encoding it, and a procedure for producing such a polypeptide by recombinant techniques are disclosed. Also disclosed are methods of using the polypeptide for a number of purposes, including: stem cell mobilization, myeloprotection, neuronal protection, treating tumors, wound healing, treating parasitic infection, and regulating hematopoiesis. Also disclosed are polypeptide antagonists and diagnostic assays for identifying mutations in nucleic acid sequence encoding a polypeptide of the present invention and for detecting altered levels of the polypeptide of the present invention for detecting diseases are also disclosed.