Two seminal papers in 2005 established the synthetic lethality between PARP inhibition and BRCA1/2 loss in preclinical models and these data, in conjunction with the proof-of-concept phase I study of olaparib, underpin the therapeutic strategy for PARPi in patients with BRCA1/2 mutant tumours [4,21,22]. This evidence concerns the gene PARP1 and neoplasm.