Pyruvate assays on Kelly (A, C) and LA-N-1 (B, D) treated for 6h (intracellular) or 24h (extracellular) with SR13800 (0.1μM), FX11 (20μM) or both drugs in combination. (E–F) In cell viability assays, the combination of SR13800 and FX11 was highly synergistic in reducing cell viability in both (E) Kelly (CI = 0.176) and (F) LA-N-1 (CI = 0.598). Data presented as means ± SD (n=3). *P<0.05, ** P<0.01, *** P<0.001, **** P<0.0001 compared to vehicle control.