We showed that BG-4 is very potent in inhibiting proliferation of both colon cancer cells, promoted apoptosis as measured by flow cytometry and microscopy study and the mechanism of action involved is through downregulation of antiapoptotic proteins Bcl-2 and XIAP, upregulation of proapoptotic proteins Bax and caspase-3 and modification of cell cycle proteins p21 and cyclin dependent kinase 2 (CDK2). The gene discussed is XIAP; the disease is malignant colon neoplasm.