MAPK9 and endothelial dysfunction: In the development of endothelial dysfunction, there has been speculation that certain mechanisms may be involved, such as the overexpression of the enzyme nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, the activation of c-Jun N-terminal kinase 2 (JNK2) [97,98], an increase in the production of superoxide anion radical (O2−) [98], an increase in the production of asymmetric dimethylarginine (ADMA) [99], and a rise in the circulating plasma levels of oxLDL [100], among other reactive oxygen species (ROS) [100].