Fig. 1

a PCA plot of mature miRNA expression in tissue, serum and exosomes samples in the discovery dataset. Dots represent samples and are colored according to sample type. b Venn diagram of differentially expressed miRNAs for the samples shown in A). Each circle represents a specific sample type comparison. c Comparison of miRNA logFC values for the exosomes vs serum (y-axis) and tumor tissue vs normal tissue (x-axis) comparisons in the discovery samples (left) and the validation samples (right). Shown are miRNAs that were significant in both comparisons (tumor vs normal and exosome vs serum) in the discovery samples. d Overall survival plot for patients in the validation dataset based on miR-21-5p expression in tumor tissue (n = 78). The y-axis shows overall survival probability and the x-axis shows survival time in months. “High” and “Low” represent miR-21-5p expression above and below the median, respectively