ATM and cancer: Although these results support and extend previous reports of ATM involvement in the activation of AMPKα by stimuli other than metformin [7, 9, 10], metformin's ability to function as a general activator of the ATM-dependent DDR pathway remains to be explored to prove a causal link between the metformin-induced activation of ATM and the diminished risk of developing cancer in individuals taking this drug [11].