Several PARP inhibitors have been shown to penetrate CNS tissue and to have a pharmacological effect, either in terms of an enhancement of the anti-tumour activity of temozolomide against intra-cranial tumours or reduction in focal ischaemia in a stroke model (Tentori et al, 2003; Hattori et al, 2004; Cheng et al, 2005; Donawho et al, 2007). The gene discussed is PARP1; the disease is Stroke.