CCDC66 and cancer: Remarkably, the oncogenic role of circRNAs in other cancers has also been considered, including circRNA_100859 (86), circAGO2 (87), PIP5K1A (88), circPPP1R12A (89), CCDC66 (90), GLIS2 (91), and circ_0084615 (92) in colon cancer, circRNA-C190 (93), circNDUFB2 (94), circ_100146 (95), circRNA_001846 (96), and circ_0087862 (97) in lung cancer, circAF4 (98), and circSPI1 (99) in leukemia.