IL6 and Alzheimer disease: In addition, inflammatory cytokines have been known to contribute to the increase of BBB permeability.29, 30, 31 To determine if the level of inflammatory cytokines increases in our AD model, we measured the levels of IFNγ, interleukin‐1β (IL‐1β), IL‐6, IL‐8, and transforming growth factor α (TNFα), all of which are associated with the increase of BBB permeability, from day 2 to day 6 in the bEC media of our two models.