TP53 and serous adenocarcinoma: Low-grade serous carcinoma (and the serous borderline tumours from which they can arise) have a high frequency of activating mutations in the MAPK pathway and generally express wild-type TP53. 7, 8, 9, 10 By contrast, high-grade serous carcinomas have almost ubiquitous TP53 mutations, defects in DNA repair capability, and gross gene copy number abnormalities.11, 12