MedicalTerminology DB

Meaning of IL-4: One of a group of related proteins made by leukocytes (white blood cells) and other cells in the body.

Definition of IL-4

One of a group of related proteins made by leukocytes (white blood cells) and other cells in the body. IL-4 is made by a type of T lymphocyte. It causes B lymphocytes to increase and to make antibodies and also increases the production of T lymphocytes. IL-4 made in the laboratory is used as a biological response modifier to boost the immune system in cancer therapy. IL-4 is a type of cytokine. Also called interleukin-4.

Written and maintained by James Murray Last updated July 21, 2026 Educational reference, not medical advice. Read the limitations.

For learning, not diagnosis. This glossary provides general educational information and is not a substitute for advice from a qualified healthcare professional. If you may be experiencing a medical emergency, contact local emergency services.