A biomarker, short for biological marker, is an objective and quantifiable measure of biological processes or states. Biomarkers can be used to deepen our understanding of a disease, or quantify its state and severity, and are critical in clinical trials in determining, at a biological level, therapeutic effect. In ALS/MND, we lack definitive, quantifiable biomarkers such as those used in other neurological diseases: tumor size in patients suffering from brain tumors, or number of lesions present on an MRI scan for those multiple sclerosis patients experiencing a relapse. Much research has been done, and is ongoing, on establishing biomarkers suitable for use in ALS/MND research and care. This webinar will provide an overview of those biomarkers emerging as the front runners for the field, and how a combinatorial approach will likely be needed.