PARP1 and neoplasm: Importantly, mutagenic therapy can elicit such reversion mutations, both in tumours and in vitro within the 1-month timescale of cell culture model experiments.16,38 Our results suggest that unlike platinum agents, PARP inhibitor treatment will not induce mutations responsible for treatment resistance, and therefore the spontaneous mutagenic processes of the tumour and the choice of additional therapeutic agents will be most relevant to the rate of the evolution of PARP inhibitor resistance.