To measure fatty acid dependency, we measured OXPHOS by inhibiting fatty acid contribution to the TCA with etomoxir (fatty acid oxidation inhibitor), and later we applied two inhibitors together, a glucose oxidation inhibitor, UK5099, and a glutaminase inhibitor, BPTES, to examine the dependency on fatty acids as described in Fig. 4B. Pure cultures of GBM cells, U87-GBM (U87), mostly use fatty acids and glucose as a major energy source; however, at least half of the energy comes from glutamine (Fig. 4C, U87 glutamine, U87, and Astro, *p ≤ 0.004 as compared to U87 cells, n = 5). The gene discussed is GLS; the disease is glioblastoma.