Models including the total number of IGF1 19-CA repeats showed CRC risk was halved at all subsites in women carrying <38 repeats but not >38 repeats (≤36 versus 38 repeats: HR for CRC = 0.44; 95% CI: 0.33, 0.58; P-trend < 0.001). Here, IGF1 is linked to colorectal carcinoma.