WNK2 and glioblastoma: For example, several mitogen-activated protein kinases (MAP4K4, MAPK9, MAPK10), growth-factor receptors (FGFR1, FGFR2, EGFR), and matricellular proteins (TNC, FN1) showed significant differences in PSI between primary and recurrent GBM (Fig. 5a, Additional file 3: Fig. S3A).