This suggests that the roles of Th17 cells and IL-17 in the etiology of RA may be multi-faceted, as the presence of Foxp3+IL-17+ T cells is observed in the subjects’ synovium (Komatsu et al., 2014; Dominguez-Villar and Hafler, 2018). The gene discussed is IL17A; the disease is rheumatoid arthritis.