PARP1 and colorectal cancer: Death receptor-mediated killing is a crucial mechanism by which NK cells eradicate tumour cells and this study has further established that PARP inhibition consistently upregulates the expression of death receptor TRAIL-R2 on tumour cells and may have utility in combination with immunotherapies such as TRAIL-R2 agonists, which are already in trials in pancreatic and colorectal cancer (NCT03082209).