APP and Alzheimer disease: Miyajima et al. (2013) concluded that t-tau, p-tau and soluble amyloid precursor protein (sAPP) and its fragments (sAPPa and sAPPb) in CSF were lower in patients with iNPH than in patients with AD, while p-tau, sAPP, sAPPa and sAPPb CSF concentrations were lower in patients with iNPH than in healthy controls [40].