IL-9 is a T cell growth factor predominately produced by antigen stimulated CD4+ T helper cells. It acts as a regulator of hematopoietic cells, stimulates proliferation, and protects T cells from apoptosis induced by IL-2 withdrawal. IL-9 enhances mast cell activity and IL-3- or IL-4- dependent proliferation of bone marrow-derived mast cells. IL-9 synergizes with erythropoietin to promote erythroid colony formation. IL-9 is upregulated in human eosinophils by TNF-alpha and IL-1beta, indicating its role in asthma and allergic diseases.BioLegend’s LEGEND MAX(TM) Human IL-9 ELISA Kit is a sandwich Enzyme-Linked Immunosorbent Assay (ELISA), in which, a Human IL-9 specific monoclonal antibody is pre-coated on a 96-well strip-well plate.BioLegend’s LEGEND MAX(TM) Human IL-9 ELISA Kit is specifically designed for the accurate quantitation of Human IL-9 from cell culture supernatant, serum, plasma or other bodily fluids. It is ready-to-use, accurate, and sensitive.