IGF1 and Familial prostate cancer: However, based on the Mendelian Randomisation analysis on cancer in the UK Biobank [45], such a difference would translate to only 1% differences in risk of colorectal (OR per 5.7 nmol/L higher IGF-1 was 1.11, 95% CI 1.01–1.22) or prostate cancer (OR per 5.7 nmol/L higher IGF-1 was RR 1.10; 95% CI 1.01–1.21).