However, the recent approval of adjuvant ipilimumab obviously has changed the therapeutic landscape for these patients and highlights the need for effective surveillance.14 The development of multiple and potentially curative immunotherapies, including high-dose interleukin-2, check point inhibitors, and ACT, make the timely identification of metastatic melanoma a high priority.15–21. This evidence concerns the gene IL2 and metastatic melanoma.