In cancer, the signaling cascade for programmed cell death, apoptosis, is often mutated leading to resistance from natural pro-death signals. PAC-1 and related compounds are small molecules capable of specifically killing cancer cells by inducing apoptosis. It does so by targeting an inactive apoptotic precursor, procaspase-3, that is up regulated in many cancer types. In vitro and in vivo studies have shown PAC-1 to be efficacious in reducing tumor cells at doses that show no toxicity in normal counterparts.