PIN1 and early-onset autosomal dominant Alzheimer disease: In the context of Alzheimer’s disease (AD), the cis/trans isomerase Pin1 has been proposed to protect against age-dependent neurodegeneration, by directly restoring the conformation and function of phosphorylated tau [13], as well as by promoting the non-amyloidogenic processing of APP and, consequently, reducing Aβ production [40].