CASP3 and cancer: To determine if apoptosis could be a mechanism by which AMP-18 exerts its dual effects on normal epithelial and HNC cancer cells observed in the orthotopic model, the effect of AMP-18 on caspase 3 cleavage as an index of cell apoptosis was compared in nontransformed HaCaT and HNC SCC-25 cells exposed to TNF-α, a proinflammatory cytokine known to mediate chemo- and radiation-therapy induced injury of the oral mucosa.