Secondly, CDC42 regulated T cell differentiation into Th1 cells and Th17 cells, while it had little effect on regulating Th2 cells in autoimmune diseases; thus, we only detected Th1 cells, Th17 cells, and their secreted cytokines in RA patients instead of Th2 cells in the current study [12, 14]. This evidence concerns the gene CDC42 and autoimmune disease.