MKI67 and neoplasm: Compared with EXOvector, the administration of EXOcirc_0001610 resulted in increased tumor volume and weight (Fig. 6A, B), a lower miR-139-5p level (Fig. 6D), and higher protein levels of cyclin B1 and Ki-67 (Fig. 6E) in the tumors of nude mice injected with EC cells.