Lately, zonulin has attracted growing attention as it shapes several neuroinflammatory diseases such as Major depressive disorders [11], Alzheimer’s disease [12], Multiple Sclerosis [13,14], Myalgic encephalomyelitis/Chronic fatigue syndrome (ME/CFS) [15], Chronic fatigue syndrome in schizophrenia [15], schizophrenia [16], and Parkinson’s disease [17,18,19]. The gene discussed is HP; the disease is early-onset autosomal dominant Alzheimer disease.