Until a tumor is determined to be TMB-high or MSI-H/MMRd, and thus qualifies for treatment with pembrolizumab or dostarlimab on the basis of cancer site-agnostic approval, there is no justification for the use of single-agent ICB in unselected populations with recurrent EOC. However, the clinical trials carried out up to this point show that ICB can induce long-lasting responses in a relatively small fraction of individuals. These discoveries offer opportunities and challenges to the medical and scientific communities, including the need to use novel technologies to locate predictive biomarkers and create immunotherapies that go beyond ICB to improve the effectiveness of these drugs.