In different models of autoimmune diseases, several miRNAs were shown to regulate Th17 cell differentiation by targeting the transcription factors that activate Th17 differentiation or decrease Treg, including RORγT, STAT3, or forkhead box P3 (FOXP3), as well as key cytokines of this process, such as IL-21R (Table 1). The gene discussed is FOXP3; the disease is autoimmune disease.