We also used a reporter construct consisting of the phospho-SMAD1/5/8 responsive ID1 promoter upstream of a luciferase gene to compare the effects of BMP2 and AB215 treatment on the human breast cancer cell lines MCF7, T47D and SK-BR-3 in the absence (Figure 1B) or presence (Figure 1C) of E2 treatment. This evidence concerns the gene ID1 and breast cancer.