POLE and endometrial carcinoma: However, considering that the mean number of somatic mutations in UCEC patients was about 850, an unusually high number of somatic mutations (from 5000 to 15,000) were identified in patients carrying mutations in INTS7 and INTS8. Hypermutation is a frequent event in cancer, and recent whole-exome sequencing analyses have revealed that the “ultramutated” phenotype associates with somatic mutations in POLE1, even in endometrial carcinoma [38].