MSH2 and endometrial cancer: Moreover, based on the present study, we found that patients with MSH6 or PMS2 mutations, compared to those with MLH1 or MSH2 mutations, were more likely to present with non-endometrioid histology (41.7% vs. 5.6%), which included clinically aggressive endometrial cancers, such as serous, neuroendocrine, clear cell, and undifferentiated cancers, which have a high risk of recurrence and mortality (Table 4).