CD40 expression has been previously reported in B-cell malignancies, as well as in a variety of solid tumors including bladder cancer, breast cancer, cervical cancer, colon cancer, gastric cancer, head and neck cancer, lung cancer, melanoma, osteosarcoma, ovarian cancer, pancreatic cancer, and renal cell carcinoma [9–11, 14–22]. The gene discussed is CD40; the disease is osteosarcoma.