A targeted approach toward the treatment of TN breast cancer by using AMPI-109 is disclosed. AMPI-109 is a compound with remarkable “cancer-specific” characteristics. In particular, AMPI-109 demonstrates a striking targeted capability to inhibit the proliferation of TN breast cancer cells and to induce apoptosis in TN breast cancer cells. The growth inhibitory effect of AMPI-109 is independent of VDR. AMPI-109 can also be coupled with other oncolytic agents in treating a patient with TN breast cancer.