Tumor necrosis factor: a master-regulator of leukocyte movement

Tumor necrosis factor (TNF)-mediated activities are potentially numerous, although in TNF-deficient (-/-) mice, altered spatial orientation of leukocytes within tissues is the predominant phenotype. Here, we propose that TNF plays a fundamental role in the control of leukocyte movement by virtue of a pivotal role in regulation of chemokine expression.