The highest prevalence of genomic alterations in MSI-H endometrial cancer was observed in MSH6 (n = 14, 23.0%), followed by MSH2 (n = 8, 13.1%), MLH1 (n = 4, 6.6%), and PMS2 (n = 1, 1.6%) (Supplementary Table S3). This evidence concerns the gene MLH1 and endometrial cancer.