IGF1 and acromegaly: Patients with acromegaly, who have high growth hormone and IGF‐1 levels, experience a 2‐fold increased risk of gastrointestinal cancers (Renehan et al., 2003), whereas patients with congenital deficiencies in IGF‐1 seem to be protected against the development of cancer (Shevah & Laron, 2007; Guevara‐Aguirre et al., 2011).