a. Gboxin inhibition of three primary human GBM cell cultures harboring different mutational spectra (ts12017, ts1156 and ts603; see Methods for details) treated with increasing doses of oligomycin A or Gboxin in the presence/absence of CsA (1 μM). n=3. Mean ± SD. b. Gboxin toxicity in multiple human cancer cell lines compared to resistant primary MEFs and astrocytes. All cells tested with the exception of Daoy cells demonstrate a therapeutic index. Mean ± SD; n=3. c-e. Top panels (Mean ± SD): Cell viability assays for Gboxin sensitive U937 & NCI-H82 (c,d), and resistant Daoy (e; IC50: 8,256 nM) human cancer cells treated with increasing doses of oligomycin A or Gboxin in the presence/absence of CsA (1 μM). Daoy cells acquire sensitivity in the presence of CsA (IC50: 1,867 nM). Bottom panels: Western blot images for OxPhos proteins from pull down assays using cells treated with B-Gboxin in the presence/absence of CsA (1 μM). Resistant Daoy cells acquire enhanced OxPhos protein interaction with B-Gboxin only in the presence of CsA. n=3.