This expression profile partially resembles that found in PD-1high MP CD4 T cells from joint synovial tissue of RA patients (Rao et al, 2017; Zhang et al, 2019) and includes expression of Il21 and Il10 which are important for extrafollicular B-cell helper function by PD-1high MP T cells in autoimmunity (Bocharnikov et al, 2019; Caielli et al, 2019), indicating the importance of Egr2 and/or 3 in the control of the inflammatory function of PD-1high MP CD4 T cells. Here, IL21 is linked to rheumatoid arthritis.