CA9 and neoplasm: Including TfR, Mammaglobin, and MUC1 to the panel of highly tumor-specific markers GLUT1, MET, EGFR, IGF1-R, CAIX, and HER2 increased the detection rate from 45.5% to 49.8% (TfR), 56.4% (Mammaglobin), and 98.1% (MUC1), respectively.