A large proportion of these tumours turned out to have hypermethylation of BRCA1. Some studies that performed aCGH profiling on BRCAX tumours find similarities with profiles of BRCA2 tumours [33], [34], suggesting that either a cause of BRCA2 inactivation in these tumours has yet to be detected or that inactivation of a number of genes can lead to a similar aCGH profile. This evidence concerns the gene BRCA1 and neoplasm.