Incompatible reactions to avirulent RKN populations in tomato rely on ROS augmented level in cells, probably due to CAT inhibition, as well as on the execution of HR based on the generation of PR proteins [18]; conversely, successful nematode infections have been found to be associated with over-expression of the glutathione peroxidase encoding gene (GPX), which is considered a potential detoxifier of H2O2 [19,20]. The gene discussed is CAT; the disease is Nematoda infectious disease.