ABCC1 and breast cancer: Spearman's correlation analysis of the data of miR-145 and MRP1 expression level in breast cancer from TCGA database and our collection showed an inverse correlation between miR-145 level and MRP1 expression level (correlation coefficient R= -0.6488; P<0.0001 in TCGA; R= -0.58; P<0.0001 in our collection) (Figure 2F and 2G).