Most cytotoxic DNA lesion: both strands severed. Sensed by MRN complex; γH2AX phosphorylation marks chromatin. Repaired by HR (S/G2) or NHEJ (any phase); unrepaired → translocations, loss.
Most cytotoxic DNA lesion: both strands severed. Sensed by MRN complex; γH2AX phosphorylation marks chromatin. Repaired by HR (S/G2) or NHEJ (any phase); unrepaired → translocations, loss.