The identification of the Th17 lymphocytes, a subpopulation of CD4+ T-lymphocytes that produces the highly proinflammatory cytokine IL-17 [9, 10], opened the way for new understanding of the physiopathological and new treatment options (secukinumab or ixekizumab) for RA [11, 12]. The gene discussed is CD4; the disease is rheumatoid arthritis.