Other studies have also found more than one PV in the same patient, suggesting that digenic/polygenic inheritance may play a role in childhood cancer etiology,[8,52,53] as MUTYH and OGG1 do in colorectal cancer etiology.[54] Kuhlen et al.[55] proposed a model of concomitant digenic inheritance involving two PVs within the same pathway combining to increase the likelihood of disease development. This evidence concerns the gene OGG1 and colorectal cancer.