Fig. 2.

Calculation of Sensitivity Index (SI) and the procedure of drug screening. a Formula to calculate the SI value for identification of potential targeted agents that synergizing the anti-glioma effect of BKM120. SI scores > 0 indicate synergy. b Workflow of target selective inhibitor screen assays, confirmations, and retesting of compounds. Drug pairs were screened in combination over fixed concentrations. Cell proliferation over 72 h in the presence of drug, relative to vehicle, was determined with Alamar Blue. Scatter plot indicating the number of inhibitors where strong synergy was observed. The cutoff for strong synergy was SI ≥ 0.12. Second round screen results displaying 110 (SI ≥ 0.12) drug measurements. Radial drug interaction plot displaying the 110 pairwise drug-BKM120 measurements. The distance from the center indicates the Sensitivity Index. SI for selected hits are indicated