It was shown, that metformin intake reduces the risk of colon cancer [35] and the protective effect of metformin appears to result from its inhibitory effect on intracellular transduction mechanisms stimulated by the activation of insulin receptor/insulin like growth factor (IGF) axis [36].On the contrary, treating of diabetes with drugs stimulating insulin release may increase the risk of cancer. The gene discussed is INSR; the disease is malignant colon neoplasm.