CHEK2 and cancer: Luteolin, a flavone found in Salvia tomentosa Mill., has been shown to delay or block the development of cancer cells, protect DNA from carcinogenic stimulus and induce apoptosis even in multidrug-resistant cancer cells by ROS generation, DNA damaging, activation of Ataxia Telangiectasia and Rad3-related/Checkpoint kinase 2/p53 (ATR/Chk2/p53) signaling, depletion of antiapoptotic proteins and inhibition of NF-κB signaling and of p38 [9].