EXT1 and glioblastoma: Sethi et al.[27] detected exostosin 1 (EXT1) and exostosin 2 (EXT2) in 21 cases of PLA2R-negative MN, but not in PLA2R-associated MN and control cases, suggesting that subset of MN is associated with accumulation of EXT1 and EXT2 in the GBM.