Multiple logistic regression confirmed male gender, CD4 cell count less than 200 cells/ml, change in head position worsens headache, and neck stiffness as significant independent predictors of a diagnosis of cryptococcal meningitis; and male gender, CD4 cell count less than 200 cells/ml, change in head position worsens headache, neck stiffness, and WHO disease stage as significant independent predictors of diagnosis of a "serious condition" (Table 5). The gene discussed is CD4; the disease is Headache.