Several reports demonstrate that interleukin-1 alpha (IL-1 alpha) and interleukin-1 beta (IL-1 beta), although distantly related at the primary sequence level, bind to the same receptor. This raises the question of what separation, if any, there might be between their biologic activities. Receptor binding assays and cross-competition studies in three Epstein Barr virus (EBV) positive cell lines...