Patients with autoimmune diseases such as RA (15, 113), SLE (16, 114), myasthenia gravis (MG) (17), primary biliary cholangitis (PBC) (115), and antineutrophil cytoplasmic antibody-associated vasculitis (116) often have an uncontrolled expansion of Tfh cells and decreased Tfr cells in the blood. The gene discussed is TFRC; the disease is primary biliary cholangitis.