IGFBP3 and breast cancer: One study has provided evidence that exercise can impact biomarkers relevant to the IGF axis: Fairey et al [25] reported significant physiological changes in IGF-I, IGFBP-3 and IGF-I:IGFBP-3 molar ratio after 15 weeks of moderate-intensity exercise training in breast cancer survivors who were, on average, 14 months post-treatment.