NOS2 and infectious meningitis: Notably, in experimental meningitis, PARP1-deficient mice and mice treated with the PARP inhibitor, 3 aminobenzamide (3-AB), display reduced leukocyte infiltration and meningeal inflammation, and this is correlated with impaired expression of Il1β, Il6 and Nos2 (Koedel et al. 2002).