PLK1 and pancreatic neoplasm: Tumor growth monitoring using intravital fluorescence imaging revealed that miR-34a/PLK1-siRNA combination therapy induced pancreatic tumor regression, inhibiting tumor growth to an average of 3.85% (111.3 ± 39 scaled counts per s) compared to tumors treated with PBS or NC-miR/NC-si (P < 0.05 for both) at day 45 (Fig. 7b).