Syk

Syk (spleen tyrosine kinase) is an enzyme inside certain immune cells that helps them respond to threats like infections or injuries. When an immune cell detects a pathogen, Syk activates signaling pathways that trigger the cell to react properly—such as producing chemicals or attacking invaders. It acts as an internal switch, translating external signals into actions that support immune defense. Proper Syk function is essential for a healthy immune response, and abnormal activity can be involved in autoimmune diseases or certain blood cancers.