In an initial group of patients with metastatic melanoma (PREDIMEL cohort) receiving either anti-PD-1 (n = 74) or combination therapy (n = 64) as first-line treatment, sCD27 concentrations, evaluated as continuous variables (Fig. 3A) or via an optimal cut-off (100 U/ml), were associated with resistance to anti-PD-1 but not with the combination of anti-PD-1 and anti-CTLA-4 (Figs. 3A and 4A,B, Table EV1). The gene discussed is CTLA4; the disease is metastatic melanoma.