PIR and cancer: Figures 6B, C show that overexpression of piR-hsa-211106 acted synergistically with PDD to inhibit A549 cell proliferation and promotes cell apoptosis, while knocking down piR-hsa -211106 reversed this inhibitory effect of PDD on A549 cells. Then we confirmed the anti-cancer ability of piR-hsa-211106 in vivo. Compared with control, treated with piR-agomir could inhibit growth of xenografts, and enhance PDD treatment efficiency (Figure 6D).