Recent advances in the generation of induced Pluripotent Stem Cells (iPSC) have opened new avenues for disease modeling based on their unique ability to contain the whole genetic background of their cell of origin as well as their capacity to differentiate and make all the cells of the body, including neurons. Investigators have collected blood samples from a large family of individuals, including both carriers and non-carriers for the E200K pathogenic mutation causing Creutzfeldt-Jakob Disease. They propose to generate iPSC-derived neurons from these cells and study the effect of the mutated prion protein in neural toxicity, as well as testing novel therapeutic compounds capable of preventing or reversing its toxic effects.