In addition, we used YOYO3, a far-red fluorescent dye, to label dead tumor cells and found that coculture of CAR-Ms and M1-polarized CAR-Ms with HER2-positive tumor cells resulted in obvious YOYO3-positive dead cells, and there were more dead tumor cells in the M1-polarized CAR-M group (Additioanl file 1: Fig. S3E, F), indicating that CAR-Ms exhibit stronger antitumor activity after M1 polarization. Here, ERBB2 is linked to neoplasm.