ATR and cancer: Therefore, SWI/SNF-deficient cancers are vulnerable to the inhibition of homologous recombination repair factor, PARP1 [20, 49], cell cycle regulator, cyclin-dependent kinase (CDK)4/CDK6 [28, 56], DNA replication checkpoint factor, ATR [57], chromosomal segregation factor, Aurora kinase A [58], and oxidative phosphorylation [59] and glutathione [60] pathways.