UBAP2 and ovarian cancer: Based on the high expression of circRNA-UBAP2 in ovarian cancer tissues and cell lines, in order to further explored the effect of circRNA-UBAP2 on biological behavior of OVCAR-3 and ES-2 cells, we either knockdown or overexpression circRNA-UBAP2 in OVCAR-3 and ES-2 cells, and verified the expression level of circRNA-UBAP2 by RT-qPCR in both OVCAR-3 and ES-2 cells (Figs. 2a, 3a).