CD80 and cancer: TZ‐dSA3‐12‐treated E0771‐HER2 cancer cells markedly increased the surface expression of activation markers, including CD40, CD80, CD86, MHC‐I, and MHC‐II on bone marrow‐derived dendritic cells (BMDCs) (Figure S5e, Supporting Information), suggesting that TZ‐dSA3‐12‐treated tumor cells enhance the antigen presentation capacity of DCs.