Because of these remaining uncertainties as to the role of brain oedema in the pathogenesis of coma in human CM, the prevalence and patterns of cerebral oedema in post-mortem brain from adult fatal malaria cases was examined, and related to factors which could influence the formation of oedema, including systemic complications of disease such as renal failure, immunohistochemical evidence of vascular integrity at the blood-brain barrier, and the expression of the water transport channel Aquaporin 4. The gene discussed is AQP4; the disease is malaria.