RAD17 and melanoma: However when used at higher doses, RHPS4 triggered short-term apoptosis/senescence in human melanoma cells [17] and a potent DNA damage response at the telomeres of transformed human fibroblasts, melanoma cells and uterine cancer cells, characterized by the appearance of the phosphorylated DNA damage response factors γ-H2AX, RAD17 and 53BPI.