IGF2 and Beckwith-Wiedemann syndrome: Insulin growth factor II (IGF-II) is a crucial fetal growth factor involved in adrenal cortex development and is present in a substantial percentage of ACC cases.14,25 IGF-II is regulated by the 11p15 chromosome locus, which includes the IGF-II coding region, H19, and CDKN1C1, among others.26 Dysregulation of this locus leads to upregulated IGF-II expression and is associated with Beckwith-Wiedemann syndrome, an adrenal phenotypic disorder.