Objective To assess the immunological relationship whom showed a higher level than the mean, and IL-6 was produced in 32 (91%) of whom 10 (29%) showed between tumour and host, focusing on the production of T-cell helper (Th) subset-derived cytokines in a higher level than the mean. IL-10 was detected in 28 patients (80%) of whom 14 (40%) showed a higher patients with renal cell carcinoma (RCC). Patients and methods The study comprised 35 patients level than the mean. The production of these cytokines was closely related to the stage and grade of malig-(19 men and 16 women, mean age 56.9 years, range 39-78) with RCC, who had undergone nephrectomy.nancy. Furthermore, there were significant correlations between the levels of production of IL-4 and Using enzyme-linked immunosorbent assays, the levels of Th1-derived cytokines were measured, including IL-5 (r2=0.92), IL-4 and IL-10 (r2=0.91), and IL-5 and IL-10 (r2=0.85). interleukin (IL)-2 and interferon (IFN)-c, and Th2-derived cytokines, including IL-4, IL-5, IL-6, Conclusion The intratumoral immunological environment in patients with RCC shows a tendency to IL-10 and others. Results There was no detectable IL-2 or IFN-c proproduce Th2-related cytokines in accordance with the stage and grade; this suggests a role in humoral but duction (below the detection limit) except in two patients; IL-4 was produced in 18 patients (51%) and not in cellular immunity. Keywords Renal cell carcinoma, immunity, T helper of these, 15 (43%) showed a higher level than the mean. IL-5 was produced in 12 patients (34%), all of subset, cytokine cytokines in patients with RCC. Based upon the results,