To determine the role and significance of these molecules in identifying Treg cells in RA patients, we detected the expression of Helios, CD226 and TIGIT on CD4+CD25hi and CD4+CD25hiCD127low/− T cells in peripheral blood and correlated the frequency to ages, gender, disease activities, and treatments in patients with RA. The gene discussed is TIGIT; the disease is rheumatoid arthritis.