Yano et al., Dundr et al., McCluggage et al. and Chapel et al. could prove clonality between the Müllerian lesions (endometrioid endometrial carcinoma, serous borderline tumor and low-grade serous carcinoma of the ovary) since they share mutations in the KRAS and NRAS gene [3,4,28]. Here, KRAS is linked to endometrial endometrioid carcinoma.