Reversions have not only been detected in tumours with BRCAm but also in tumours with mutations in other HRR genes such as PALB2 [50], RAD51C and RAD51D [51] (Figure 1), which reinforces the notion that mutations outside of BRCA genes that impact HRR are valid selection biomarkers for PARPi therapy. This evidence concerns the gene PALB2 and neoplasm.