Anti-Interleukin 9 antibodies are used for the immunodetection of the protein encoded by the IL9 gene. In humans, the canonical protein has a reported length of 144 amino acid residues and a mass of 15.9 kDa. It is known to be a secreted protein. A member of the IL-7/IL-9 protein family, it is known to be involved with B cell differentiation and inflammatory response pathways. Post-translational modifications have been described, including glycosylation. Other names 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. Gene orthologs have been identified in the mouse, rat, bovine and chimpanzee species. Over 270 citations in the literature describe the use of Interleukin 9 antibodies in research. ELISA is a widely used application for these antibodies. In addition, Flow Cytometry is also a common application.