25–30% of the endometrial MLA cases harbor additional mutational events within the PTEN-, CTNNB1-, and ARID1A-genes (Mirkovic et al. 2018; Kolin et al. 2019; Euscher et al. 2020; da Silva et al. 2021; Mills et al. 2022; Ma et al. 2022) which are also common mutational alterations in endometrioid endometrial carcinomas. This evidence concerns the gene ARID1A and endometrial endometrioid carcinoma.