ATM (ataxia-telangiectasia mutated) is a PI3K-like kinase best known for its role in the DNA damage response (DDR), especially after double-strand breaks.
Formation of DNA double-strand breaks, as monitored by comet assay was examined in an ATM (ataxia-telangiectasia mutated)-dependent manner based on the fact that PI3K inhibitor Wortmannin abolished the action of cytotoxicity of 5-Aza-CdR.