Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) is the most important enzyme in oxidative stress, and it has been reported that Ca2+/calmodulin-dependent protein kinase II (CaMKII), a well-described serine-threonine kinase related to cardiovascular diseases (11), can be oxidized by NOX at methionines 281 and 282 to form oxidized CaMKII (ox-CaMKII) (12). This evidence concerns the gene CAMK2G and cardiovascular disorder.