IL2 and renal cell carcinoma: Klapper et al. reported the expanded NCI Surgery Branch experience for 259 patients with advanced renal cell carcinoma who were treated between 1986 and 2006 with high-dose IL-2 at the dose of 720,000 units per kilogram IV bolus every 8 hours up to a total of 15 doses per cycle (later reduced to a maximum of 12 doses).