ARID1A deficiency was found to sensitize cancer cells to poly adenosine diphosphate (ADP) ribose polymerase (PARP) inhibitors and inhibitors of the DNA damage checkpoint kinase, ataxia telangiectasia and Rad3-related (ATR), providing rationale for clinical testing of PARP and ATR inhibitors [17, 18]. This evidence concerns the gene ARID1A and cancer.