Several circRNAs (circ0004390, circHIPK3, circPIP5K1A, circUBAP2, circ-ABCB10, hsa_circ_0051240, circ FAM53B) exert their oncogenic roles in ovarian cancer cells.[13,14,18,19,21,26,39] For instance, circPIP5K1A acts as a sponge of miR-661 to promote ovarian cancer progression via regulation of IGFBP5. Here, IGFBP5 is linked to ovarian cancer.