Mutations in app, ps-1 and ps-2 genes result in the appearance of Familial Alzheimer disease (FAD). Although, in many cases, those mutations result in an increase of the amount of beta amyloid peptide, there is not a clear correlation between that amount and the time of the onset of the disease. Thus, other factors may explain how mutations in those genes result in the appearance of neurodegeneration. In this minireview we propose that GSK3 could be one of those factors.