Altered expression of brain-specific S100 proteins is associated with decreased motor and cognitive skills and neurological damage characteristic of Alzheimer’s disease (AD) and Parkinson’s disease, and several members of the S100 family are found in the amyloid plaques and cerebrospinal fluid of AD patients [4,5,6,7]. The gene discussed is S100A1; the disease is early-onset autosomal dominant Alzheimer disease.