To our knowledge, this study is the first to demonstrate durable objective tumour responses to PARP plus PD-L1 inhibition in a gallbladder adenocarcinoma, cholangiocarcinoma, neuroendocrine carcinoma, a uterine perivascular epithelioid cell tumour (PeCOMA) and high-grade glioma, all selected on the basis of somatic or germline HRR gene alterations. Here, CD274 is linked to neuroendocrine carcinoma.