MRC1 and endometrial cancer: The objective of this study was to determine the value of MMR protein status in predicting response to different adjuvant therapies in a retrospective cohort of patients with endometrial cancer that were classified into molecular subgroups by immunohistochemistry of MMR proteins and p53, and sequencing of POLE. In addition, we studied MLH1 methylation status as a predictor of treatment response in MMR deficient (MMR‐D) endometrial cancers.