ABCG2 and breast cancer: Significantly decreased levels of mRNA transcripts were about 0.5-fold lower with respect to the ABCG2 gene detected in both BC cells treated with UA compared to the control group (Figure 2E), as well as a significant reduction in CSC markers, including the Nanog and Oct4 genes (by >60%) in cell lines treated with 30 μM UA compared to the control (Figure 2G,H).