IGF1 and neoplasm: The uncontrolled cell proliferation associated with malignant transformation is often correlated with acquired resistance to apoptotic cell death, through several molecular mechanisms, including the loss of p53 tumor suppressor activity, upregulation of anti-apoptotic (Bcl-2, Bcl-Xl) or pro-survival (IGF-1/2) factors, downregulation of pro-apoptotic factors (Bax, Bim, Puma), and inactivation of effector caspases (Figure 2).