Monocytes/macrophages are known to express uPAR (Min et al.,1992; Vassalli et al.,1992), and levels of expression are reported to be elevated during endotoxemia and by various cytokines including IL-1β, TNF-α, and TGFβ1 (Dekkers et al.,2000; Yue et al.,2004). Here, TNF is linked to serum lipopolysaccharide activity.