Finally, it is important to note that IL-17A production is not strictly associated to Th17 cells, since it is produced also by additional cells of the immune system enriched in SF of JIA patients, such as CD3+CD8+ and CD3+CD4-CD8- T cells (17, 61, 62) and innate lymphoid cells (62). The gene discussed is IL17A; the disease is juvenile idiopathic arthritis.