IGF1 and Familial prostate cancer: There was some evidence that the inverse association between SHBG and prostate cancer incidence varied by IGF‐I concentration (Phet = .02); only men with lower concentrations of IGF‐I (< the study median) had a reduced risk of prostate cancer (HR per 10 nmol/L increment in SHBG = 0.94, 95% CI 0.92‐0.97, Figure 4).