H2AX and cancer: The cytotoxic mechanism behind this can be illustrated as arrested cancer cells at the G2/M phase, decreased cell viability by activating caspase cascade, increased PARP cleavage, and γ-H2AX expression as well as induced autophagy by upregulation of Bectin-1, autophagy related 5 (ATG5), LC-3, and formation of ROS [63].