Bone marrow (also known as myeloid tissue) is a red, soft, semi-solid, gelatinous tissue, which is found in the axial skeleton. It is highly vascular and enriched with many blood vessels and capillaries. Deep within the bone marrow resides a type of cell known as mesenchymal stem cells (MSCs). These immature cells can differentiate into cells that produce bone, cartilage, fat, or muscle. Researchers are also able to identify a wide range of cell progenitors that are found within the bone marrow, which, in turn, helps them understand and identify causes of blood and autoimmune diseases. Consequently, access to normal bone marrow is crucial to the advancements in clinical research, and treatment of disease.