DRD2 and rheumatoid arthritis: In a small cohort study of patients with rheumatoid arthritis, B cell DRD expression was lower than that of healthy controls, B cell DRD2 stimulation is negatively correlated with disease activity (Wei et al., 2015), and DRD2 and − 3 expression levels were increased among patients treated for 3 months with an anti-rheumatic disease modifying drug (Wieber et al., 2022).