Furthermore, we observed that binding of CSF-derived HGF to the c-Met receptor could differentiate meningitis from other causes of fever in patients that had undergone neurosurgery; this assay had quite high specificity (=93 %), and it could rule out nosocomial meningitis in 88 % of cases (negative predictive value, 88 %; Table 2a). The gene discussed is HGF; the disease is infectious meningitis.