To test the hypothesis that lycopene or green tea influence circulating IGF peptides in men at elevated risk of cancer (defined pragmatically in our study as men with prostate specific antigen (PSA) levels between 2.0 and 2.95 ng/ml or PSA ≥ 3 ng/ml but negative biopsies), we measured serum levels of IGF-I, IGF-II, IGF binding protein (BP)-2 and IGFBP-3 at baseline and after 6 months of an intervention in which men were randomized to daily lycopene and green tea (the ProDiet trial) (Lane et al., 2010). The gene discussed is KLK3; the disease is cancer.