Studies have shown that hsa _circ_0001610 is overexpressed in M2-Exos and transferred to endometrial cancer cells, and negatively regulates the expression of miR-139-5p in endometrial cancer cells by directly binding to miR-139-5p, upregulating the expression of cyclin B1, thereby attenuating the radiosensitivity of endometrial cancer cells (56). This evidence concerns the gene CCNB1 and endometrial cancer.