CD9 and breast cancer: CD9 is overexpressed in precursor B-ALL, AML, glioblastoma, gastric carcinoma and breast cancer.78, 79, 80, 81, 82 A CD9 antibody-producing B cell was isolated from the B cells of a patient that was cured of stage IV metastatic melanoma after adoptive T-cell therapy (abstract EACR2018).83