RAD51 and neoplasm: The “synthetic lethality” conferred by PARPi (Martin et al. 2008; Lord and Ashworth 2017) is not only restricted to BRCA1- and BRCA2-mutated tumours but also to neoplasia harbouring genetic alterations in other HR genes, such as ATM, RAD51, PTEN, XRCC2, etc (Bang et al. 2013; Kelley et al. 2014), this suggesting a therapeutic potential role of PARP inhibition in a wide range of human malignancies.