Eosinophil white blood cell, illustration - stock illustration

Eosinophil white blood cells. Computer illustration of eosinophil white blood cells, showing their lobed nuclei (purple). Eosinophils, like all white blood cells, are part of the immune system. They are responsible for combating multicellular parasites and certain infections. Along with mast cells, they also control mechanisms associated with allergy and asthma. They are granulocytes that develop during haematopoiesis in the bone marrow before migrating into blood.