We should also state that the MMR genes, MLH1 and MSH2, were found downregulated in our lung cancer patients—a fact supported by previous studies which show that reduced expression of MLH1 and MSH2 was found in >50% of lung adenocarcinomas and was associated with poor survival and an increase in microsatellite instability [38]. This evidence concerns the gene MSH2 and lung adenocarcinoma.