IL3 and systemic lupus erythematosus: To explore the possibility of multiple infusions of Fox19CAR-Tregs and to verify their efficacy in a later stage of disease, we adapted the SLE model to SGM-3 mice, a strain characterized by a constitutive high expression of human IL-3 and GM-CSF, able to better promote human HSC engraftment, and characterized by a longer lifespan than humanized NSG mouse pups39.