Overview:

Interleukin 9 (IL9) is an immunoregulatory cytokine belonging to the IL-7/IL-9 cytokine family. Commonly produced by TH17 cells, IL9 acts as a hematopoietic cell regulator by preventing apoptosis and stimulates cell proliferation of T lymphocytes, erythroid cells, and mast cells. It binds to the IL9 receptor (IL9R) to activate different signal transducer and activator (STAT) proteins. It also supports IL2 and IL4 independent growth of helper T-cells and affects TH17 and Tregs through STAT3 and STAT5 signalling activation. Furthermore, IL9 has been found to be a candidate gene for asthma as its presence determines the pathogenesis of bronchial hyper-responsiveness. Although human and mouse IL9 share a 56% amino acid identity, human IL9 is not active on mouse cells and can be found to inhibit melanoma growth in mice.

Gene Aliases:

P40, T-cell growth factor P40

Genbank Number:

P15248