MLH3 and neoplasm: Since SWNTS-SWNs harbored higher CNV and 22q LOH relative to NS-SWNs and both tumor types displayed the MMR COSMIC signatures 6 and 15, we assessed the expression of MMR and DNA repair-related genes and found that MSH3, MSH6, PMS2 and MLH3 were significantly upregulated in SWNTS-SWNs relative to NS-SWNs (Student’s t test, q < 0.01, Fig. 4d).