TLR2 and Alzheimer disease: As we have described earlier, impaired TLR2 function plays a role in driving loss of barrier integrity and the immune system imbalance (Th2 dominance) during the acute phase of AD, but aberrant activation of TLR2 may lead to Th1 immune development during the chronic phase of AD and may also lead to the production of keratinocyte-specific cytokine TSLP that drives the allergic immune responses.