CD28 and neoplasm: To boost the cytotoxic potential of TAC-T cells against solid tumors, we generated a novel NECTIN-4-targeted TAC-T variant, NECTIN-4 TAC28-T, which integrated the co-stimulatory CD28 cytoplasmic region, and compared the anti-tumor activities between NECTIN-4 TAC-T cells and NECTIN-4 TAC28-T cells in vitro and vivo.