Transferrin (TF) subtypes were studied in 7 different populations from the Soviet Union (Buryats, Russians, Koreans, Kirghizes and Pamirians) and in 3 different populations from Mongolia. The frequency of the C2 gene varied between 10.4% in Pamirians and 27.4% in Koreans and was generally higher in populations of Mongoloid origin. The frequency of the C3 gene was found to be very low (nonpolymorphic) in the Mongoloid groups, but it was also low (1.5%) in Russians. Rare B and D variants were found in 7 populations. The highest D frequencies were found in the Mongoloid populations.