IGF1 has mitogenic and antiapoptotic properties (Khandwala et al. 2000), and has been positively correlated in some preclinical, epidemiologic and case–control studies with modestly increased risk of several cancers, particularly hormone-dependent cancers of the breast and prostate (Renehan et al. 2004, Pekic & Popovic 2013, Crawley & Holmberg 2014). Here, IGF1 is linked to cancer.