PDIA4 and central nervous system cancer: ONCOMINE data mining indicated that the expression of DNAJC10, TMX1, PDIA4, PDIA5, PDIA6, P4HB and TXNDC5 was significantly up‐regulated in brain and CNS cancers when compared with normal tissue; however, the expression levels of TMX4 and PDIA2 were higher in normal brain samples than in brain cancer tissues (Figure 2A).