PDIA4 and lung adenocarcinoma: Of the 16 distinguishing proteins, 8 were significantly elevated in lung adenocarcinoma (COPG1, STOML2, HYOU1, PDIA4, EPRS, APEX1, LRPPRC and NANS) whereas 8 proteins were significantly decreased in lung adenocarcinoma (SPTB, SPTA1, ANK1, SLC4A1, HBG1 and HBG2).