c-Myc is required for USP18-mediated pancreatic cancer growth. (A) Overexpression of ectopic c-Myc attenuated the loss of c-Myc expression in BxPC-3/shUSP18 cells. (B–D) CCK-8 assay, Edu assay and flow cytometry show that the overexpression of ectopic c-Myc significantly rescued the decreased cell proliferation ability of BxPC-3/shUSP18 cells, *p<0.05. (E) Results are expressed as the calculated percentage of Annexin-V-positive cells. *p<0.05. (F) Knockdown of c-Myc expression markedly inhibited the increase in c-Myc expression observed in SW1990/p-USP18 cells. (G–I) CCK-8 assay, Edu assays and flow cytometry demonstrate that c-Myc inhibition significantly reduced the USP18-enhanced cell proliferation observed in SW1990/p-USP18 cells. (J) Results are expressed as the calculated percentage of Annexin-V-positive cells. *p<0.05.