Spleen

The spleen performs two distinct biological functions: blood filtration and immune surveillance. It removes aged or damaged red blood cells, stores iron from haemoglobin breakdown, and hosts a large population of lymphocytes and macrophages that respond to pathogens circulating in the blood.

Spleen naturally contains heme iron.

Tuftsin and splenopentin are small peptides found exclusively or primarily in spleen tissue. Spleen tissue naturally contains the peptides tuftsin and splenopentin. Both represent the frontier of whole-organ immune research.