EXO1 and cancer: Surprisingly, in present study we found that variant genotypes of K589E were associated with risk of CRC by applying robust Bayesian approach as the same as numerous studies which have demonstrated several SNPs of Exo1 as genetic risk factors of cancer (14, 16) for example in Taiwanese and Chinese population it was obtained that the A allele of this polymorphism has a significant association and increase the risk of lung cancer (17, 18).