qRT–PCR showed significantly higher lncRNA DLEU1 expression in EOC tissues than in normal ovarian tissues, benign ovarian tumours and borderline ovarian tumours (Fig. 1A, P < 0.05), and lncRNA DLEU1 expression was positively associated with differentiation (well versus. poor and moderate, Fig. 1B, P < 0.05), and International Federation of Gynecology and Obstetrics (FIGO) staging (stage I versus. stage II/III/IV, Fig. 1C, P < 0.05). This evidence concerns the gene DLEU1 and ovarian benign neoplasm.