ERBB2 and breast cancer: Several of the fused genes are also recurrently broken in a substantial proportion of breast cancers, as judged by copy number steps in array-CGH of 1000 breast tumours [47]: around 10% have breaks in ERBB2, BCAS3 and SKAP1, while COL14A1, TIAM1, USP32, TAOK1 are broken in around 4%.