PDIA3 and glioblastoma: Another potential role in modulation and interaction between GBM cells and GAMs might be played by the ERp57/PDIA3 (protein disulfide-isomerase A3), an endoplasmic reticulum protein present both in GAMs and GBM cells, whose expression and activity were found to be directly proportional to the polarization capacity towards the protumor M2 phenotype of microglia [35].