These observations are in agreement with those from studies of the 19q12 amplicon in gastric cancer, where CCNE1 was amplified only in a subset of cases harbouring 19q12 amplification [59], and with those of previous studies that have found a prevalence of CCNE1 amplification in 1.2% to 1.4% of primary breast cancers [14,60]. This evidence concerns the gene CCNE1 and breast cancer.