Widespread multifocal ductal carcinoma in situ (DCIS) was detected both adjacent and distal, and within separate mammary glands, to many of the Ctip/p53-deficient breast carcinomas, suggesting that one or more of these pre-invasive foci likely progressed to form the invasive carcinoma (data not shown). Here, TP53 is linked to ductal breast carcinoma in situ.