IFNG and nonpapillary renal cell carcinoma: Despite the occurrence of rare, prolonged complete remissions in patients with metastatic melanoma and ccRCC [126, 127], the use of high-dose IL-2 was restricted by the significant, often fatal adverse events and the need for intensive monitoring and experience in its administration, whereas the use of IFNg in ccRCC was characterized by its perceived low efficacy [128].