MSH2 and adenoma: Unlike what was published by Engel et al. in the so-called three countries study (Finland, Germany and Netherlands), which described a lower incidence of adenomas and advanced adenomas in MLH1 carriers (MLH1 vs. MSH2; 32.2% and 7.7% vs. 44.2% and 17.9%, respectively), many other recent studies have failed to clearly show such difference [21, 25–27].