Effects of expression levels of miRNA programs and ceRNAs on ceRNA regulation. (A, B) Density functions and cumulative distribution functions of correlation coefficients of putative ceRNA pairs. The putative ceRNA pairs were split into groups by quartiles of miRNA programs expression levels. (C) Density functions of correlation coefficients of putative ceRNA pairs. Here the putative ceRNA pairs were categorized based on expression states (i.e., H, M, and L) of their composed ceRNAs. (D) Cumulative distribution functions of (C), focused on comparison of ceRNA pairs composed of two highly expressed genes (H-H) to other ceRNA pairs and non-ceRNA pairs.