CD276 and neoplasm: Through a series of carefully designed in vitro and in vivo experiments, we have demonstrated that the Cr3+ ions released from this versatile platform can elicit robust antitumor immunity by strengthening the cytotoxic effect of B7‐H3 CAR‐T cells, as indicated by the increased expression of perforin and granzyme, the extensive formation of TLSs, and the enhanced tumor infiltration of CAR‐T cells (Figure 1).