Among these presumptive AD biomarkers are calcineurin subunit β, a serine/threonine phosphatase under the control of Ca2+/calmodulin; β-synuclein, which is associated with synaptic degeneration; α-synuclein, which is associated with the occurrence of comorbid LRP in AD; and FKBP prolyl isomerase 1B (FKBP1B), a chaperone involved in age-related Ca2+ dysregulation in the brain. The gene discussed is SNCA; the disease is Alzheimer disease.