The potential of tumoricidal myeloid cells to serve as final mediators of tumor rejection has recently become more appreciated; for example, Beatty et al. demonstrated for both mouse and human pancreatic carcinoma a likely pivotal role of tumor-infiltrating myeloid cells activated to a tumoricidal state through an agonal CD40 mAb [14, 65]. The gene discussed is CD40; the disease is neoplasm.