CUL2 and glioblastoma: Similarly, ID2 binds to VHL in glioblastoma tumor cells and disrupts the binding of CUL2 to the VHL–elongin B–elongin C–CUL2 (VCB-CUL2) complex, which prevents ubiquitin-mediated proteasomal degradation of another HIF-1 family member, HIF-2α, and promotes the survival of glioblastoma stem cells (GSCs) (53).