(UroToday.com) At the ASCO 2020 virtual education program, Janice Dutcher, MD, discussed the beginnings of immunotherapy for renal cell carcinoma (RCC) as part of the evolution of RCC treatment session of talks. Cytokines are endogenous substances within the immune system and are responsible for cell signaling, as well as induction or inhibition of various cell regulatory proteins and processes. Several cytokines have clinical importance to RCC including interferon alpha, beta, and gamma, as well as interleukin-2 (IL-2). There are several key biological actions of interferons: