The American Academy of Arts and Sciences (AAA&S) is one of the oldest learned societies in the United States.

An antigen is a substance that triggers an immune response in the body.

A blood transfusion is a medical procedure where blood is transferred from one person (the donor) to another person (the recipient).

Bone marrow is a soft, gelatinous tissue found within the hollow spaces of bones.

DNA, also known as deoxyribonucleic acid, is a molecule that carries the genetic instructions used in the growth, development, functioning, and reproduction of all known living organisms and many viruses.

Gene is a widely recognized online encyclopedia that provides information on a wide range of topics, including biology, genetics, and other related fields.