CD40 and neoplasm: For example, in proof-of-principle studies we have shown that targeted, partial depletion of macrophages by anti-F4/80 antibody (approximately 40% reduction of F4/80hi cells only) in aged tumor-bearing female C57BL/6J mice (20–24 months) improved response to IL-2/anti-CD40 immunotherapy, i.e. increased cytotoxic lymphocyte activity, reduced treatment-associated cachexia and tumor regression [58].