KNG1 and Alzheimer disease: However, extrapolating the findings of this study, it can be hypothesized that an additional immune challenge, in this case by LPS, leads to the reduction of beneficial microglial functions evoked neuropeptides such as bradykinin and somatostatin -even if those are decreased in AD brains as stated above, since the increased Aβ uptake observed in response to these neuropeptides is compromised by pre-exposure to LPS.