Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder characterized by the loss of motor neurons (specialized nerve cells) in the spinal cord, brain, and descending motor tracts. ALS leads to muscle weakness and paralysis, and is often fatal. Numerous biochemical processes have been linked to the progression of ALS, including increased levels of protein modification (phosphate units). Xiaoyang Shan is researching the role of modified sugar units, known as O-GlcNAc, in maintaining the proper functioning of neurofilaments (structural proteins) that give neurons support and shape but become damaged in ALS patients. He is also investigating the role of O-GlcNAc in maintaining healthy motor function. The findings could help increase understanding of the causes of ALS, and contribute to development of a potential treatment to slow or halt the progression of the disease.