In a 2013 observational cohort study of 1,705 colorectal cancer patients, Rodríguez–Soler et al [47] demonstrated the incidence of colorectal cancer in families of patients with MMR-deficient tumours was significantly lower than in families of patients with Lynch syndrome but higher than in families of patients with MMR-intact (p < 0.001). This evidence concerns the gene MRC1 and colorectal cancer.