SMAD1 and breast carcinoma: On the other hand, Reverse Phase Protein Array (RPPA) data for the breast cancer patient cohort, where it is possible to analyze the change in β-CATENIN protein level, did not include either BMP2/BMP6 or phosphorylated SMADs (SMAD1/SMAD5) or direct target genes of BMP pathway such as ID1–3.