At 72 h reperfusion when systemic immunosuppression is apparent after cerebral ischemia (Prass et al., 2003), bone marrow cells showed no difference in LPS-induced IL-6 production in vitro as assessed in cell lysates (Figure 4A) and cell culture supernatants (Figure 4B), indicating that at this time point cells residing in the bone marrow maintain their ability to respond to endotoxin. This evidence concerns the gene IL6 and brain ischemia.