To determine whether lupus patients would respond in the same way as healthy donors regarding sCTLA-4 production by PBMC stimulated by antigens rather than autoantigens, we examined a panel of stimulants, including PPD recall antigen, SEB superantigen, and agonist anti-CD3 mAb (Fig. 3b). Here, SETBP1 is linked to systemic lupus erythematosus.