Hu19-CD828Z is a second-generation CAR-T construct targeting CD19 with a fully human anti-CD19 antibody and a CD8α hinge/transmembrane (H/TM) domain fused to CD28 and CD3ζ signaling; in five SLE patients, Hu19-CD828Z–derived CAR-T cells showed CD19-dependent proliferation with markedly low release of inflammatory cytokines IL-2, IL-6, and IL-1β (37, 38). Here, CD28 is linked to systemic lupus erythematosus.