In prostate cancer, elevated insulin or C-peptide levels (used as a normalised surrogate) have recently been shown to significantly correlate with high-grade prostate cancer and worse patient prognosis [16, 31–36], more significantly than BMI alone, suggesting that at least part of the effect of increased BMI on prostate cancer mortality is related to coincident hyperinsulinaemia [33]. The gene discussed is INS; the disease is Familial prostate cancer.