AG1024 (Tyrphostin AG 1024), one selective inhibitor of IGF-1R, was used to evaluate effects on proliferation, radiosensitivity, and radiation-induced cell apoptosis in a human breast cancer cell line MCF-7. AG1024 inhibited the mitogen-activated protein kinase/extracellular signal-regulated kinase pathway and restored pRb tumor suppressive function. Human breast cancer cell studies report AG1024 to induce apoptosis, inhibit cell proliferation, decrease bcl-2 and phospho-Akt1 expression, and elevate the expression levels of Bax, p53 and p21. Studies report AG1024 to block tyrosine kinase activity and to have a lower IC50 for IGF-1 in comparison to insulin receptors. Other studies indicate that exposure of SHR cells to AG1024 decreases Ang II-mediated NAD(P)H oxidase activation.