Insulin-like growth factor II (IGF2) is perhaps the most intricately regulated of all growth
factors characterized to date. Its gene is imprinted–only one allele is active, depending on
parental origin–and this pattern of expression is maintained epigenetically in almost all
tissues. IGF2 activity is further controlled through differential expression of receptors and IGF-
binding proteins (IGFBPs) that determine protein availability. This complex and multifaceted
regulation emphasizes the importance of accurate IGF2 expression and activity. This review …