CRBN and central nervous system cancer: Likewise, treatment with proteasome or neddylation inhibitors (MG132, bortezomib [36] or MLN4924 [37]) in CRBN KO glioma cells could also increase the Slo1 levels, though treatment with bortezomib or MLN4924 in WT cells for excessive time led to decreased Slo1 levels, likely due to compound cytotoxicity (Fig 5F and 5G).