PDCD1 and metastatic colorectal cancer: Thereby, the newly discovered drug SX-682, inhibitor of the CXCR1/2 chemokine receptors, is currently in a phase I clinical trial to determine if it is an effective treatment for metastatic melanoma patients in combination with pembrolizumab (anti-PD-1) (NCT03161431) and whether it could be beneficial in combination with nivolumab (anti-PD-1) as a maintenance therapy in subjects with metastatic PDAC (NCT04477343) or metastatic colorectal cancer (NCT04599140).