The phenomenon of parental imprinting has become increasingly important in 
disciplines such as evolution, genetics, molecular biology, embryology and 
pathology. Principally, parental imprinting refers to a parent-of-origin 
dependent expression of a subset of autosomal loci, independent of the sex of 
the offspring. Today, at least seven such loci have been identified, including 
the human IGF2 gene. It appears that the set of imprinted genes is not always 
identical between the species, although the importance of maintaining this kind 
of gene regulation is evolutionarily conserved. It is particularly interesting 
from the clinical point of view that a number of human diseases, such as the 
Beckwith-Wiedemann and Prader-Willi/Angelman syndromes, appear to involve 
unbalanced parental contributions of imprinted loci. We show here that the four 
different human IGF2 promoters are expressed mono- and/or biallelically in 
complex patterns in postnatal liver specimens.