TP53 and endometrial cancer: In the past two decades, the clinical validation of molecular subtypes of EC has yielded a stepwise algorithm, the Proactive Molecular Risk Classifier for Endometrial Cancer (ProMisE) [63], which requires the testing of pathologic mutations of the endonuclease domain of polymerase epsilon (POLEmut), as well as the evaluation of p53 expression patterns and mismatched repair (MMR) protein levels by immunohistochemistry.