IGF1 and neoplasm: Indeed, tumor cells develop strategies to limit or circumvent apoptosis, such losing the p53 tumor suppressor function, increasing expression of anti-apoptotic regulators (the Bcl-2 protein family) or survival signals (Igf1/2), downregulating pro-apoptotic factors (Bax), or avoiding the extrinsic ligand-induced death pathway (Hanahan and Weinberg, 2011).