Elevated circulating IGF-I also has been found to be a potential cancer risk factor for cancers of other organs, such as the prostate (Mantzoros et al, 1997; Chan et al, 1998; Wolk et al, 1998; Stattin et al, 2000) and the colorectum (Ma et al, 1999; Giovannucci et al, 2000; Kaaks et al, 2000; Palmqvist et al, 2002). Here, IGF1 is linked to cancer.