IL17-A is a member of the IL-17 family which is constituted by 6 members (IL-17A to IL-17F). IL-17A is commonly refer to as IL-17 and is produced as a homodimer of about 30 kDa. IL-17A is mainly secreted by a subset of CD4 + T cells, namely the Th17 cells, which are helper cells that are distinct from Th1 and Th2 cells. In addition to Th17 cells, other immune cells such as γδ T cells, CD8+ T cells, NK cells and Innate Lymphoid cells (ILCs) can be activated to secrete IL-17. IL-17 is a pro-inflammatory molecule that induces the production of chemokines and other cytokines by various cell types, i.e fibroblasts, epithelial cells, endothelial cells, macrophages and neutrophils, which helps the recruitment of innate immune cells at the site of activation. *Alexa Fluor and Pacific Blue are registered trademarks of Molecular Probes, Inc.