ERBB2 and breast carcinoma: Similarly, Tong et al. reported that RT-qPCR scores of HER2 FISH equivocal tumors were independent of FISH HER2/CEP17 ratio and HER2 copy number,10 whereas in HER2 unequivocal breast cancer, tight correlation between RT-qPCR and FISH ratio/copy number is seen.5