Hence, to enhance treatment efficacy and minimize drug resistance, the HER2-directed CAR approach has been developed and validated in diverse tumor-bearing mouse models, including those of osteosarcoma (Rainusso et al., 2012), breast cancer (Sun et al., 2014), renal cancer (Schonfeld et al., 2015), and glioblastoma (Zhang et al., 2016). This evidence concerns the gene ERBB2 and breast cancer.