TP53 and melanoma: In conclusion, the activation of pro-apoptotic proteins such as p53, caspases 9 and 3, and the down regulation of survival proteins such as PARP-1 and AKT as well as the increased expression of γH2AX protein, strongly suggest that hydroxytyrosol treatment induces the death for apoptosis through the activation of intrinsic apoptotic pathway in melanoma cells.