Amyotrophic Lateral Sclerosis (ALS) is a disease that affects the nerve cells in the brain and spinal cord, causing loss of muscle control. This study is about understanding how a protein in the blood, called neurofilament light chain (sNfL), is connected to ALS. The goal is to see if this protein can show how fast ALS is getting worse and help doctors predict the course of the disease. The Single Molecule Analysis method (SIMOA) will be used to study 3,000 ALS patients. This is a large, multi-center study, meaning it takes place in several locations.

• The study will need participants to give blood samples for testing.
• Participants must be 18 years or older and willing to share medical data.
• The research will help understand ALS better and may guide future treatments.

People who participate will help scientists learn if sNfL can be used as a marker to track ALS progression or response to treatments. This research could be important for finding new ways to manage or treat ALS in the future.