—Molecules or fragments of molecules that belong to a foreign invader that can elicit an immune response. These may include germs, toxins, and tissues from another person used in organ transplantation.
—Proteins (chemical messengers) that are predominantly released by immune cells upon activation or stimulation that help bring about tumor cell death.
—A cell whose daughter cells may differentiate (develop into other cell types).
Kausalya Santhanam Ph.D., The Gale Group Inc., Gale, Detroit,