To explore the potential of the combination treatment with ZSTK474 and PD-1 blockade, we employed tumor cell lines (CMS5a and B16F0) that are resistant to PD-1 blockade.23 Mice-bearing CMS5a cells stably expressing a tumor antigen, NY-ESO-1 (CMS5a-NY-ESO-1) were treated with ZSTK474. The gene discussed is PDCD1; the disease is neoplasm.