An even greater and statistically significant difference was observed for ethanol-treated constitutive Aldh1b1−/− Msh2-LS mice showing colonic hyperproliferation and tumour formation (67% of animals), in an average of 6 months of ethanol treatment, compared with 0% control water-treated constitutive Aldh1b1−/− Msh2-LS mice with hyperproliferation/neoplasm formation. This evidence concerns the gene MSH2 and neoplasm.