Peter Spencer, PhD, FANA, FRCPath, Oregon Health & Science University, Portland, OR, discusses how the evidence from Guam can be used to understand amyotrophic lateral sclerosis (ALS) worldwide. If sporadic ALS can be caused by environmental factors, the latency period spans several years to decades. This enables a large therapeutic window for intervention. However, the challenge is to identify the primary drivers of the disease and the types of chemicals which are responsible. This interview took place during the Virtual World Congress on Controversies in Neurology (CONy) 2020.