Anti-IL9 antibodies are used in the immunodetection of the protein interleukin 9. In humans, the canonical protein has a reported length of 144 amino acid residues and a mass of 15.9 kDa. It has been described to be a secreted protein. A member of the IL-7/IL-9 protein family, IL9 is known to be involved with B cell differentiation and inflammatory response pathways. Post-translational modifications have been described, including glycosylation. Synonyms for this target antigen include P40, T-cell growth factor p40, cytokine P40, homolog of mouse T cell and mast cell growth factor 40, p40 T-cell and mast cell growth factor, and HP40. IL9 gene orthologs have been reported in the mouse, rat, bovine and chimpanzee species. Over 270 citations in the literature describe the use of IL9 antibodies in research. ELISA is a widely used application for these antibodies. In addition, Flow Cytometry is also a common application.