Fig. 2

Clinical course and changes of the serum level of soluble interleukin-2 receptor (sIL-2R). The serum sIL-2R level (normal range: 135.0–483.0 U/ml) was measured before cytoreductive nephrectomy (pre-op) and every 1 to 3 months after nephrectomy (post-op). a Two patients showed a response to first-line and/or second-line therapy, but then gradually developed resistance along with elevation of sIL-2R. Although they subsequently received second-line or third-line therapy, respectively, they did not respond and sIL-2R continued to increase until death. b Two patients had relatively long-term stable disease while receiving first-line to third-line therapy. In these patients, sIL-2R remained stable or decreased gradually over time. c Two patients showed a good response to first-line, second-line, or third-line therapy. In these patients, the sIL-2R level generally remained within the normal range or decreased toward the normal range. d Two patients had a poor response to first-line and second-line therapy. In both patients, the sIL-2R level initially elevated and continued to rise further until death