Your body is a fortress. Every day, it protects you against threats great and small. The body's outer defenses keep microbes outside. If the outer defenses are breached and pathogens enter the body, cellular and molecular soldiers are mobilized. The shock troops are white blood cells, some armed with anti-microbial proteins.
Antibodies are smart missiles.
They specifically recognize foreign molecules as foes associated, for example, with pathogens or infected host cells. In theory, antibodies could treat cancer or immune disorders as well. It was not until the development of genetic engineering in the 1970s that antibodies could be made to order for therapeutic use. Since then, antibody genetic engineering has progressed further with the development of improved recombinant manufacturing and more human-like antibodies.