We herein report for the first time that three subgroups of long non-coding RNA define the biological diversity of endometrioid endometrial carcinomas; of note, while basal-like and luminal-like EEC subgroups correlated well with breast carcinoma signatures, the CTNNB1-enriched subgroup correlated with CTNNB1-mutated liver carcinomas. The gene discussed is CTNNB1; the disease is endometrial endometrioid carcinoma.