Migration inhibitory factor's (MIF's) eponymic activity was the first cytokine-mediated function
to be described, but the protein resisted cloning, purification, and molecular characterization
until recently (1). MIF is now known to be produced abundantly by monocytes/macrophages
and to act in an autocrine/paracrine fashion to up-regulate and sustain the activation
responses of diverse cell types (2). Stimulation of macrophages with Gram-negative
endotoxin (lipopolysaccharide), Gram-positive exotoxins (toxic shock syndrome protein-1 …