For AdnaTest the global contribution to CTC positivity at baseline was driven by EPCAM (19.4%), MUC1 (16.1%), and their combination (29.0%), whereas the contribution of ERBB2 was not relevant considered either alone (3.2%) or in combination with EPCAM (6.5%). EPCAM and MUC1 were the most represented markers among CTC-positive samples especially in patients with metastatic disease, where positivity for CEA and EGFR was also observed though at low frequency. The gene discussed is ERBB2; the disease is metastatic neoplasm.