Treatment of late-stage melanoma patients with immune checkpoint blockade (ICB) is currently one of the most effective standard therapies. The response rates upon neoadjuvant ICB in stage III melanoma are higher as compared to stage IV disease. Given that successful ICB depends on systemic immune response, we hypothesized that systemic immune suppression might be a mechanism responsible for lower response rates in late-stage disease, and also potentially with disease recurrence in early-stage disease.