We present a case study of a long term PARP inhibitor responder - a germline BRCA2 mutation carrier with advanced ovarian cancer – who despite achieving an excellent response to PARP inhibitor monotherapy, twice developed radiological disease progression of liver metastases, arguably secondary to the selection of a BRCA2 proficient clone, potentially from an heterogeneous primary tumor [23, 24]. The gene discussed is BRCA2; the disease is ovarian cancer.