When HER2 status were defined with ddPCR and FISH, the ddPCR HER2:CEP17 ratio in patients with HER2 amplified tumor (median 4.08, range 0.93–24.84) was significantly elevated compared to HER2 non-amplified cases (median 0.93, range 0.32–2.00, P < 0.001) (Fig. 1B). The gene discussed is ERBB2; the disease is neoplasm.