Previous studies have shown that stromal deletion of BMPR2 could facilitate carcinogenesis in CRC and breast cancer, suggesting tumor-suppressive functions of mesenchymal BMP signaling.28,29 Moreover, augmentation of BMP signaling mediated either by increased BMP ligand or decreased BMP antagonist secretion from the tumor mesenchyme, which occurs as a consequence of stromal Hedgehog signaling activation, restrains bladder cancer or CRC progression.22,30 Our work supports these findings and provides novel insights into regulatory mechanisms of BMP signaling in the CRC tumor microenvironment. The gene discussed is BMPR2; the disease is breast carcinoma.