CD4 and rheumatoid arthritis: Given that activated CD4+ and CD8+ T cells contribute to the pathophysiology of inflammatory diseases including MS, RA, sarcoidosis, and autoimmune uveitis (Kolios et al., 2021), inhibition of T cell activity may lead to improved outcomes in patients with these diseases (Chitnis, 2007; Oswald-Richter et al., 2013; Peeters et al., 2017).