We assessed the genetic instability at p53, Mdmx and Mdm2 using high resolution multi-color fluorescent in situ hybridization (FISH) protocol and detected the expression status of the tumor protein p53 (TP53), MDMx and MDM2 by immunohistochemistry in 115 archived samples of infiltrating ductal breast carcinomas with foci of ductal carcinoma in situ (DCIS) components. Here, TP53 is linked to invasive ductal breast carcinoma.