The best cut-off values taken from the co-ordinates of the ROC curve (see methods section) below which cerebral malaria was more likely than presumed viral encephalitis were: CSF white cell count, 4 cells/μl; CSF protein level, 0.43 g/l; CSF glucose, 3.4 mmol/l; CSF LDH, 22.5 IU/ml; CSF/serum ADA ratio, 0.385 (Table 2). The gene discussed is ADA; the disease is viral encephalitis.