The levels of ABCG2, C-Myc, Bmi1, and Sox2 were repressed by the depletion of circNOLC1 in MDA-MB-231 and MDA-MB-468 cells (Fig. 3E and F), implying that the inhibition of circNOLC1 attenuates cancer stem cell properties. This evidence concerns the gene ABCG2 and cancer.