We further analyzed the effects of GREB1 mRNA on patients’ survival using the data from the North Central Cancer Treatment Group Trial, Tamoxifen (TAM) arm of 89-30-52 which recruited 225 patients (Phase III trial of adjuvant therapy with Tamoxifen alone or combined with Fluoxymesterone in postmenopausal women with resected estrogen receptor positive breast cancer) [48], [49], [50]. This evidence concerns the gene GREB1 and breast cancer.