IGF1R and osteosarcoma: There are efforts to block tumor-stromal signaling crosstalk by small molecule inhibitors, for example NT157 that leads to the irreversible elimination of an important IGF-1R signaling protein, the Insulin receptor substrate 1 and 2 (IRS-1/2), and that has pharmacological effect in osteosarcoma and prostate cancer in preclinical studies, but there are no results for breast cancer yet [47].