Among the 33 equivocal cases due to an altered CEP17 status by DDISH, MLPA found 4 (12%) HER2 amplified BC (mean value ≥1.5, Fig. 2), 2 (6%) with a gain (mean value ≥1.3, but <1.5) and the remaining 27 non amplified (mean value <1.3) In the latter cases, we found a 55,5% concordance rate between DDISH and MLPA (Cohen’s K statistic: -0.043, 95%CI:[−0,271–0,184]). This evidence concerns the gene ERBB2 and breast cancer.