When they were infused intravenously into tumor-bearing severe combined immunodeficiency (SCID) Beige mice (MUC1-targeting CAR-T for MDA-MB-435 breast cancer, and ErbB-targeting CAR-T for HN3 human head and neck squamous cell carcinoma), the engineered CAR-T cells distributed in the murine lungs, liver, and spleen without significant penetration into the tumor. The gene discussed is MUC1; the disease is neoplasm.