Breast cancer SK-BR-3, MDA-MB-231 and MCF10A cell lines were transfected by using Polyamidoamine (PAMAM) dendrimers and constructs encoding a luciferase/PE38 under the control either of the CMV or/CXCR1 promoter with or without the insertion of a bFGF 5′UTR. This evidence concerns the gene CXCR1 and breast cancer.