Compared with the previous meta-analysis, the present study includes more studies and individuals and thus might produce a more comprehensive result than the study of RA et al. [44] that identified vascular endothelial growth factor (VEGF), bcl2, p16 and bax but not Smad4 as immunohistochemical prognostic markers in pancreatic cancer. The gene discussed is SMAD4; the disease is pancreatic neoplasm.