MUC1 and breast cancer: CAR targeting MUC1 derived from monoclonal antibodies specific to the tumor-associated MUC1 glycoforms was developed, and its antitumor efficacy has been demonstrated in multiple epithelial cancers including ovarian cancer, adenocarcinoma, leukemia, pancreatic cancer, head and neck squamous cell carcinoma, cholangiocarcinoma, and breast cancer [19].