A vast variety of interleukins (particularly IL-4 and IL-31), chemokines (CXCL9 and CXCL10), neuropeptides (substance P), hormones (cortisol) and even allergen specific IgE (for example against Dermatophagoides pteronyssinus) were linked to abnormal sleep in AD [18]. This evidence concerns the gene IL4 and Alzheimer disease.