Interestingly, given the dual effect of IL-21 in stimulating effector lymphocytes and inhibiting Th17 mediated responses, the combination of IL-21 and anti-PD-1 antibody is currently being studied in a phase I dose escalation study in advanced or metastatic solid cancers, and IL-21 combined with ipilimumab is being studied in a phase I trial in advanced melanoma (NCT01629758, NCT01489059). This evidence concerns the gene IL21 and melanoma.