FBXO22 and glioblastoma: Then, we transfected HA-Ub-K48 plasmid or HA-Ub-K63 plasmid with Flag-VHL plasmid into U87 cells to detect the detailed ubiquitin type of FBXO22-mediated VHL ubiquitination by IP assays in GBM cells (Fig. 4M).