The latest in a series of articles on immunotherapies aimed at clearing out the build up of cellular aggregates involved in Alzheimer's disease: "Immunotherapy targeting the age-related accumulation of extracellular aggregates, in the form of ß-amyloid, is the first rejuvenation biotechnology to reach Phase III human clinical trials. The promise of this therapy for the treatment and prevention of Alzheimer's disease (and ultimately, of so-called 'normal' brain aging) has sparked an interest in utilizing the same approach for other forms of aging damage, including the clearance of aggregated intracellular proteinaceous aging damage. Notably recent years have seen the appearance of a rising number preclinical studies of therapeutic vaccines targeting pathological tau species accumulating in the brains and spinal cords of transgenic rodent models of tauopathic neurodegeneration. These studies have reported -- somewhat surprisingly -- the antibody-mediated clearance of these primarily intracellular aging lesions, accompanied by functional improvements in treated animals. These two forms of structural damage are major contributors to the age-related degeneration of the brain, whether it leads to frank dementia or to the diagnostic euphemism of 'normal' age-related cognitive decline, and novel therapeutics to effect the removal of both from aging neurons will be key elements of a comprehensive panel of rejuvenation biotechnologies."