Comparison of RE-scores between ER+ and ER- samples from five breast cancer expression datasets. (a) Box plots of RE-scores for miR-371. miR-371 shows significantly higher RE-scores in ER- than in ER+ samples for all five datasets. The statistical significance level of difference (FDR) for each dataset is also shown. (b) Distributions of the t-scores for RE-score comparison between ER- and ER+ samples. The t-scores for 470 miRNAs were calculated by comparing their RE-scores for ER- samples with those for ER+ samples. The t-score distributions for the five datasets are shown in different colors. Most t-scores are positive, indicating that most miRNAs exhibit higher RE-scores in ER- than in ER+ samples. (c) Proportion of RE-changing miRNAs with higher inhibitory effect in ER- samples (red) and RE-changing miRNAs with lower inhibitory effect in ER- samples (green) at three different significance levels (FDR ≤ 0.05, FDR ≤ 0.10, and FDR ≥ 0.20). The number on the top of a bar represents how many RE-changing miRNAs were identified from the corresponding mRNA microarray dataset. HE, MI, MN, VA and WA represent the microarray data published by Hess et al. , Miller et al. , Minn et al. , van't Veer et al. , and Wang et al. , respectively.