Ana deployed Shun-Yuan Jiang’s S-30 cells stably transfected with the wild-type ER gene and Bill Catherino’s BC-2 cells stably transfected with Asp351Tyr to determine whether keoxifene, a failed breast cancer drug with none of the estrogen-like properties of tamoxifen, would have a different molecular pharmacology via the Asp 351Tyr ER at a TGFα target. This evidence concerns the gene ESR1 and breast cancer.