The MaxDiscovery™ Human IL-5 ELISA Test Kit is designed for quantitative determination of the concentration of human IL-5 in serum, plasma, and cell culture supernatant. Human interleukin-5 (IL-5) is a ~13 kDa polypeptide of 115 amino acids after cleavage of a signal peptide. It is mainly produced by T cells in response to stimulation by parasite-derived antigens and allergens. IL-5 is a specific hematopoietic growth factor responsible for the growth and differentiation of eosinophils. It promotes the growth of immature hematopoietic progenitor cells. IL-5 strongly stimulates the proliferation, cell activation, and differentiation of eosinophilic granulocytes. IL-5 also promotes the generation of cytotoxic T-cells from thymocytes. Some asthmatic patients and cancer patients using IL-2 immunotherapy showed elevated levels of serum IL-5.