For quite some time, anti-CD28 antibodies have been used as artificial co-stimulatory ligands, particularly in the activation of tumor-antigen-specific lymphocytes.31, 32 Some other humanized antibodies with co-stimulatory capacity, such as antibodies for CD40, OX40, and 4-1BB, are currently in clinical trials.33 The gene discussed is CD40; the disease is neoplasm.