IGF1 and acute lymphoblastic leukemia: We did not control for components of the insulin-like growth factor (IGF) system; the limited existing evidence for this system refers to ALL rather than AML (Ross et al, 1996; Petridou et al, 2000) and the association between adiponectin and IGF-1 in children is not strong enough to generate considerable confounding (Mantzoros et al, 2004a).