In the mid-13th century, Genghis Khan's Mongol hordes swept across the Russian plain, seizing Moscow and imposing their rule over much of the country for the next 250 years. Almost eight centuries later, it seems that genetic traces the Mongols left behind are partly to blame for Russia's traditional weakness for alcohol. The gene, known as ADH2-2, is common in Asian countries but almost non-existent among Europeans. Carriers of the gene are more susceptible to the effects of drinking and more likely to become alcoholics. Since alcohol consumption was rare among Asiatic tribes, they evolved differently from Europeans, who have a long tradition of producing and consuming alcohol. The culture of drinking has existed for centuries in Europe, dating back to before the Roman Empire, so Europeans have built up a natural resistance. Scientists have long known that the ADH2-2 gene is common among Russians, but Ogurtsov et al. [] were the first to test how it affects alcohol consumption. There is a negative correlation between the ADH2-2 allele and alcohol misuse (both alcoholic dependence and alcoholic cirrhosis). This correlation is expressed more in alcoholic dependence. Among many other negative characteristics, it has also been found that those with the gene were more likely to have negative emotional responses (like aggression and depression) and more likely to suffer withdrawal symptoms [Mainville, ].