Whereas some authors (Pollak, 2000; Yu and Rohan, 2000) have hypothesised that the relative levels of IGF-I to IGFBP-3 may be important for cancer risk, the absolute quantities (reflecting total body stores) may be more pertinent, remembering that IGFBP-3 circulates in molar concentrations considerably (five-fold) greater than IGF-I. Here, IGFBP3 is linked to cancer.