PEA and URB597 potentiate cell death of B16 melanoma cells. Apoptosis was assessed by Annexin-V (A)/Propidium Iodide (PI) staining. B16 cells were treated with 10 μM of PEA and/or URB597 for 24 h and the number of Annexin-V positive cells (A+/PI-, apoptotic) and of double stained cells (A+/PI+, necrotic) was expressed as a percentage of total cells. Data are the average of five random fields from experiments performed in triplicate. Significantly different (**P < 0.01) from vehicle incubation.