CSF samples from patients with Alzheimer’s disease had significantly higher binding affinity to HSPG and c-Met compared to samples from patients with aseptic meningitis (p < 0.0001), samples from controls (p < 0.0001), and samples from patients that had undergone neurosurgery and had infections other than meningitis (p < 0.0001) (Table 1; Fig. 2). Here, MET is linked to infection.