In the present study, we used IVM to demonstrate that PARP inactivation in leukocytes drastically attenuated leukocyte adhesion/migration to and across cortical vessels in two in vivo models, LPS-induced systemic inflammation, and TNFα-induced localized encephalitis (Fig. 2), whereas autologous leukocytes displayed regular adhesion. The gene discussed is PARP1; the disease is viral encephalitis.