In addition to these promising pre-clinical studies, there are ongoing clinical studies examining CXCR2 antagonism in combination with immune checkpoint inhibitors; SX-682 in combination with pembrolizumab (anti-PD1) for the treatment of metastatic melanoma (NCT03161431), SX-682 in combination with nivolumab (anti-PD1) for metastatic pancreatic ductal adenocarcinoma (NCT04477343) (Table 1). This evidence concerns the gene PDCD1 and metastatic melanoma.