DRD2 and alcohol drinking: Following the seminal findings of our group in 1990 related to the association of the DRD2 Taq A1 allele (located in exon 11 of the ANNKI gene) with severe alcoholism, 31 years later, along with an explosion of new genetic techniques (e.g., genome-wide association studies), genetic polymorphisms linked to extreme violence/aggression have been discovered.