A novel function for fibroblast growth factor 21: stimulation of NADPH oxidase-dependent ROS generation.

Fibroblast growth factor 21 (FGF-21) is a major paracrine and endocrine regulator of metabolic homeostasis. Here we demonstrate that FGF-21 is also a potent mediator of innate immunity. Double-staining flow cytometry identified neutrophils and monocytes as the main sources of FGF-21 among circulating leukocytes.