TNFRSF4 and Arthritis: Interestingly, patients with RA have been shown to have an abundance of OX40+ Tfh cells capable of producing IL-17 (86), and OX40 was enhanced on Tfh cells within the lymph nodes and demonstrated that severity of arthritis was reduced by blockade using anti-OX40L in glucose-6-phosphate isomerase-induced arthritis.