MLH1 and neoplasm: Our findings suggested that a higher risk of regional LNM in dMMR/MSI colorectal cancer was associated with older age, tumor in the left colon and rectum, high-grade differentiation, T3–T4 invasion, neural invasion, vascular invasion, and negative IHC staining results for MMR proteins except for the double-negative staining of MLH1 and PMS2 or MSH2 and MSH6 (Tables 1-3).