EGFR and neoplasm: To this end, five groups of MDA-MB-468-Erl-R tumor-bearing mice received i.v. injections of PBS (Group I), erlotinib (Group II), Tet-HER1-CAR-T cells (Group III), Doxy plus Tet-HER1-CAR-T cells (Group IV) and Doxy@CaCO3-PEG plus Tet-HER1-CAR-T cells (Group V) twice (Fig. 6E).