CXCR5 and chronic hepatitis B virus infection: In another hand, excessive activation of Tfh cells would contribute to the production of autoantibodies and lead to autoimmune diseases.It was reported that circulating CXCR5+CD4+T cells were expanded in patients with chronic hepatitis B[30, 31] and high frequency of circulating CXCR5+CD4+T cells were associated with HBeAg seroconversion through IL-21 production manner[31, 32].Our preliminary works have also shown the expansion of circulating Tfh cells and their associated molecules in patients with chronic HBV infection [33].