Heat map and unsupervised hierarchical clustering of 26 differentially expressed miRNAs. The heat map diagram shows the result of the two-way hierarchical clustering of genes and samples. Each row represents a miRNA and each column represents a sample. The miRNA clustering tree is shown on the left, and the sample clustering tree appears at the top. The colour scale shown at the bottom illustrates the relative expression level of a miRNA across all samples: red represents an expression level above mean, blue represents expression lower than the mean. The clustering is performed on log2(Hy3/Hy5) ratio which passed the filtering criteria on variation across samples; standard deviation > 0.50. miR172b* was not followed up in other experiments.