INS and diabetes mellitus: Although the epidemiological evidence related to HbA1C and cancer is limited, the key biological causal factors relate to the anti-apoptotic, proliferative and mitogenic nature of insulin and insulin-like growth factor (IGF) and the impact that hyperglycaemia has upon mortality risk.[35–37] If a causal association were to be found between raised HbA1C and mortality from CVD and other causes then some of the differences found in mortality between those with and without diabetes could be overcome through stricter glycaemic control.