HER2 has been targeted with 2nd and 3rd generation CAR T cells in breast cancer [35, 36], gastric cancer [37], glioblastoma [38], sarcoma [39], ovarian cancer [40], and osteosarcoma [41].The majority of studies have clearly demonstrated that the incorporation of co-stimulation molecules, such as CD28, 4-1BB, OX-40, ICOS, or CD27 [30, 36, 42–44] into CAR constructs offers better therapeutic benefit in preclinical and clinical settings. Here, ERBB2 is linked to breast cancer.