To understand better the cooperativity between p53 and ERs in the regulation of FLT1 promoter and the response to genotoxic stress, we evaluated the role of ERs in the p53-dependent transactivation of the FLT1 using a clone of the p53 wild-type breast adenocarcinoma MCF7 cell line which is positive for ERα and has low ERβ expression. This evidence concerns the gene ESR1 and breast adenocarcinoma.