NOS2 and asthma: In a cohort of 727 African American and Dominican children diagnosed with asthma, Jung et al [76] demonstrated that V exposure decreases the DNA-methylation of IL4 and IFNγ promoters, and when stratified by overweight status and asthma, a relationship was observed between V exposure and hypomethylation of NOS2 A. These effects can lead to gene low expression, which could alter the allergic immune response.