Our study shows that gene expression profiling is able to distinguish TP53 haploinsufficient breast epithelial and stromal cells from matched tissue from an individual with wild-type TP53. These data suggest that genomic profiling can help define molecular targets for chemoprevention and biomarkers of breast cancer risk impacted by early alteration in TP53. Significantly, pharmacological intervention with the p53 rescue compounds CP-31398 and PRIMA-1 provided further evidence in support of the central role of p53 in affecting these changes in LFS cells and treatment for this cancer. This evidence concerns the gene TP53 and breast cancer.