Differential miRNA expression between BC and BO. The expression value zero was set as one to be visible on logarithmic coordinates. The normalized expression values were used to evaluate the difference between two kinds of datasets. Black spots refer to breast cancer cancerous tissue datasets and black circles depict breast noncancerous tissue datasets. A. Expression data for known breast cancer associated miRNAs. B. Expression data for the 10 best class-separating miRNAs. Rows are sorted according to raw p-values. These data including a previously breast cancer associate miRNA (shown in Figure 3A) as well as newly identified differentially expressed miRNAs.