IL6 and renal cell carcinoma: We looked for predictive modulations of response to treatment by evaluating serum levels of VEGF and fibronectin, known to have a prognostic value in MM and RCC, and pro-inflammatory cytokines (IL-1β, IL-6, IL-8, IL-10, TNFα, IL-12 p70) known for their involvement in local and systemic immune response.