CCL17 and Alzheimer disease: Among the dysregulation of immune responses in AD, keratinocytes initiate cross-talk between innate and adaptive immune responses by regulating the release of several key molecules including eotaxin/CC chemokine ligand (CCL) 11, eotaxin‐3/CCL26, monocyte chemotactic protein (MCP)‐4/CCL13, regulated on activation, normal T cell‐expressed and secreted (RANTES)/CCL5, and thymus and activation‐regulated chemokine (TARC)/CCL17, that trigger inflammatory reactions and immune responses (138).