Mainly, variations of candidate genes (e.g., DRD4, DAT1, 5-HTTLRP), aspects of temperament (especially reactivity, inhibitory control, effortful control), parental ADHD symptoms, and neonatal brain volume, were all found to moderate the relation between environmental factors and the developmental outcomes of ADHD and EF. This evidence concerns the gene SLC6A3 and attention deficit-hyperactivity disorder.