We report that in mice bearing kidney or breast adenocarcinomas that present a defined low-avidity epitope derived from hemagglutinin model antigen, bortezomib administration at 1 mg/kg body weight augments the expression of lymphocyte-stimulatory cytokines IL-2, IL-12, and IL-15 and their downstream signaling molecules. The gene discussed is IL15; the disease is breast adenocarcinoma.