For AML and some ALL cells, most ROS production could be counted (about 60%) by NOX (NADPH oxidase) activity 58 and, since some cancer cells have an impaired antioxidant system, the ROS overproduced by ultrasound has a more negative effect on viability leading to unbalance oxidative status and high oxidative stress causing caspases activation, mitochondrial damage, and finally late apoptosis. This evidence concerns the gene FMO5 and acute lymphoblastic leukemia.