Consistent with the analysis of miR-21 and DDX5 mRNA expression levels using TCGA datasets (Supplementary Fig. 5c), DDX5 protein levels are positively correlated with miR-21 levels, determined by immunohistochemistry staining of HER2+ breast tumor tissue microarray (Fig. 4d and Supplementary Fig. 5d). Here, ERBB2 is linked to breast neoplasm.