PDIA4 and adenocarcinoma: Consistent with our proteomic data, mRNA expression of APEX1, HYOU1, PDIA4, NANS, LRPPRC, EPRS and COPG1 were significantly (Mann–Whitney U < 0.05) higher in adenocarcinoma compared to control whereas mRNA abundance of HBG1, HBG2, HBD, and PTRF were significantly (Mann–Whitney U < 0.05) lower (Additional file 1: Figure S1).