Immune checkpoint inhibitors, such as antibodies that block negative regulators of T-cell activation (such as CTLA4 and PD-1/PD-L1), have transformed cancer treatment. However, even in metastatic melanoma and non-small cell lung cancer (NSCLC), malignancies that are highly responsive to immune checkpoint inhibitors (ICI), response rates rarely exceed 40%. Not only that, many common malignances, such as prostate cancer and pancreatic ductal adenocarcinoma, are ICI refractory but causes of treatment failure are largely unknown. It is known though that oxaliplatin triggers a form of cell death that is thought to be immunogenic, whereas the chemical analogue cisplatin does not trigger the same form of immunogenic cell death. Recent clinical trials have shown that immune checkpoint inhibitors responsiveness is significantly augmented by combining PD-1 signaling inhibitors with platinoid chemotherapeutics. Such results have led to approval of immune checkpoint inhibitors + platinoid combination therapy in NSCLC but the basis for this synergism has not been determined.