This application focuses on a key protein that damages the neurons in Alzheimer's disease. It is called hyperphosphorylated tau protein. We found that the loss of certain key molecules in neurons, called microRNAs, is strongly associated with the formation of this neurotoxic protein. When microRNAs are lost then proteins that they normally suppress can be made in large amounts and effect the function of the cells. We have found that in Alzheimer's disease the loss of specific miRNAs allows the expression of at least two mRNAs and proteins that can allow the cell to accumulate neurotoxic proteins. Importantly, we have also shown that in our preliminary work that one of these mRNAs called cFLIP is much increased in the CSF of people with Alzheimer's disease. Thus, this work may well develop novel and important biomarkers of Alzheimer's disease and hopefully allow the diagnosis to be made early in the disease process.