2014). Previous research has demonstrated that IL-17 is overexpressed in RA patients. Inhibiting the generation of Th17 cells and secretion of IL-17 cytokine can improve RA symptoms. However, Treg cells (CD4+CD25+Foxp3+) can also prevent autoimmune responses by secreting anti-inflammatory cytokines. IL-10 suppresses the expression of Th17 cells and promotes Treg cells (Heo et al. 2010). TGF-β1 plays an important role in Treg cell generation and expansion in peripheral tissues (Sun et al. 2019), which can prevent and protect against autoimmune arthritis (Astry et al. 2015; Lee et al. 2018). Here, CD4 is linked to rheumatoid arthritis.