Breast cancer MCF-7 cells were transiently transfected with either a reporter-luciferase construct containing 1.7 kilobase of the wild-type BRCA1 promoter (pGL3BRCA1, -1552 to +140 from +1 on exon-1b) or the pGL3BRCA1 construct carrying mutated Sp (pSpmut, 5'-GGctaaGAA-3') or CRE (pCREmut, 5'-CtgcA-3'). The gene discussed is BRCA1; the disease is breast carcinoma.