MARK2 and cancer: The integrated stress response(ISR) is one of the pathways that cancer cells activate to avoid celldeath.4 ISR is a set of signaling pathwaysthat regulate cellular responses to various factors such as ER stress,hypoxia, oxidative stress, and nutrient deficiency, and thus helpsto restore cellular homeostasis.5,6 The ISR stress signalsare transmitted via four serine/threonine kinases: GCN2, HRI, PERK,and PKR, which all phosphorylate the translation initiation factor.Cancer is often treated with therapeutic agents acting on the integratedstress response.