ISG15 promotes malignant biological behaviors of PC cells. A, Proliferation of PC cells with or without ISG15 depletion as determined by CCK-8 assay. B, Representative images of colony formation assays. C, Effects of ISG15 knockdown on cell migration capacity as valued by wound healing assay. Representative images are shown (scale bar; 100 μm). D-E, Representative images of chamber migration (D) and invasion assays (E) designated for evaluation of cell migration and invasion capacity, respectively (scale bar; 100 μm). F-G, Effects of ISG15 depletion on spheroid formation. Representative images are shown (F) with statistic results (G) (scale bar; 50 μm). (*** p<0.001).