Researchers tested what changes happen in volunteers with ALS that can be seen in the blood and what changes are unique to ALS and are different from those found in healthy volunteers and volunteers with neurological diseases other than ALS. These changes are called biomarkers. Biomarkers for ALS have been found in blood collected in earlier phases of this study. Biomarkers are non-genetic elements in your blood that may help to make diagnosing ALS easier. In the next phase, comparison of these changes in the blood of volunteers with ALS and without ALS will be used to confirm these biomarkers and to develop a tool to diagnose and monitor progression of ALS.