Although not significantly or trend-wise modulated in the MCI/AD CSF, the significantly elevated levels of systemically-derived IL-1β, eotaxin, and MIP-1α may have contributed to the pro-inflammatory CNS state, since these factors can cross the blood–brain barrier [126,127,128], and the blood–brain barrier was previously shown to be disrupted in MCI/AD cases [115]. Here, IL1B is linked to Alzheimer disease.