Up to now, a variety of molecular epidemiological studies have been conducted to estimate the association between the RAD51 135G/C polymorphism and risk of various cancers [9-17], including squamous cell carcinoma of the head and neck [18-21], colorectal cancer [22-25], ovarian cancer [26-28] and acute leukaemia [29-37]. This evidence concerns the gene RAD51 and colorectal cancer.