Primary cold agglutinin disease (CAD) is a rare form of autoimmune hemolytic anemia. Surbhi Sidana, MD, Mayo Clinic, Stanford, CA, outlines the study investigating the presence of post-translational glycosylation as a potential mechanism for IgM modification. Results show changes in the IgM immunoglobulin structure by post-translational glycosylation of light chains were significantly more common in patients with CAD compared with other IgM monoclonal gammopathies. The presence of light chain glycosylation can provide diagnostic clues and can be a potential therapeutic target. This interview took place at the American Society of Hematology (ASH) 2019 Annual Meeting and Exposition in Orlando, FL.