In order to demonstrate the direct involvement of miR-31 in the regulation of these genes in cancer cells, we tested the effect of miR-31 mimics and inhibitor on the expression of STAB2, RHOA, WAVE3 and other relative genes after transfection into MCF-7 and SUM-159 cells (Figures 3A, C; Supplementary Figure 5). The gene discussed is WASF3; the disease is cancer.