B cells: White blood cells that develop from bone marrow and produce antibodies. Also called B lymphocytes.

B lymphocytes: White blood cells that make antibodies and are an important part of the immune system. B lymphocytes come from bone marrow. Also called B cells.

B3 antigen: A protein found on some tumor cells.

B43-BAP immunotoxin: A toxic substance linked to an antibody that attaches to tumor cells and kills them.

Bacteria: A large group of single-cell microorganisms. Some cause infections and disease in animals and humans. The singular of bacteria is bacterium.

Bacterial toxial: A toxic substance, made by bacteria, that can be modified to kill specific tumor cells without harming normal cells.

Barbiturate: A drug with sedative and hypnotic effects. Barbiturates have been used as sedatives and anesthetics, and they have and they have been used to treat the convulsions associated with epilepsy.

Barium enema: A procedure in which a liquid with barium in it is put into the rectum and colon by way of the anus. Barium is a silver-white metallic compound that helps to show the image of the lower gastrointestinal tract on an x-ray.

Barium solution: A liquid containing barium sulium sulfate that is used in x-rays to highlight parts of the digestive system.

Barium swallow: A series of x-rays of the esophagus. The x-ray pictures are taken after the person drinks a solution that contains barium. The barium coats and outlines the esophagus on the x-ray. Also called an esophagram.

Barrett's esophagus: A condition in which the cells lining the lower part of the esophagus have changed or been replaced with abnormal cells that could lead to cancer of the esophagus. The backing up of stomach contents (reflux) may irritate the esophagus and, over time, cause Barrett's esophagus.

Basal cell carcinoma (BAY-sal sel kar-sin-O-ma): A type of skin cancer that arises from the basal cells, small round cells found in the lower part (or base) of the epidermis, the outer layer of the skin.

Basal cells (BAY-sal): Small, round cells found in the lower part (or base) of the epidermis, the outer layer of the skin.

Basophil: A type of white blood cell. Basophils are granulocytes.

Batimastat: An anticancer drug that belongs to the family of drugs called angiogenesis inhibitors. Batimastat is a matrix metalloproteinase inhibitor.

BAY 12-9566: An anticancer drug that belongs to the family of drugs called angiogenesis inhibitors.

BBR 3464: A substance that is being studied as an anticancer drug. It belongs to the family of platinum-based drugs.

BCG vaccine: An anticancer drug (bacille calmette-Guerin) that activates the immune system. Filling the bladder with a solution of BCG is a form of biological therapy for superficial bladder cancer.

Bcl-2 antisense oligodeoxynucleotide G3139: A drug that may kill cancer cells by blocking the production of a protein that makes cancer cells live longer. Also called augmerosen.

Becmerosen: A drug that may kill cancer cells by blocking the production of a protein that makes cancer cells live longer. Also called augmerosen.

Benign (beh-NINE): Not cancerous; does not invade nearby tissue or spread to other parts of the body.

Benign prostatic hyperplasia (hye-per-PLAY-zha): A benign (noncancerous) condition in which an overgrowth of prostate tissue pushes against the urethra and the bladder, blocking the flow of urine. Also called benign prostatic hypertrophy or BPH.

Benign tumor (beh-NINE): A noncancerous growth that does not invade nearby tissue or spread to other part to other parts of the body.

Benzaldehyde: A colorless oily liquid used as a flavoring agent and to make dyes, perfumes, and pharmaceuticals. Benzaldehyde is chemically related to benzene.

Benzoylphenylurea: A substance that is being studied as an anticancer drug. It belongs to the family of drugs called antitubulin agents. Also called BPU.

Beripla BPU: A substance that is being studied as an anticancer drug. It belongs to the family of drugs called antitubulin agents. Also called BPU.

Beta alethine: A substance that is being studied as a treatment for cancer. It belongs to a family of chemicals called disulfides.