We are in the midst of an exciting revolution in the treatment of cancer. By harnessing and enhancing the body’s immune system using novel therapies such as immune checkpoint inhibitors, we can reduce the amount of tumor burden in patients and, in a subset of patients and cancers, achieve long-lasting remission. However, these therapies are often limited by treatment-induced autoimmune adverse events. They affect nearly every organ system, ranging widely from minor rashes and fevers to severe gastrointestinal, pulmonary, or cardiac complications. Dr. Kerry Reynolds, along with Dr. Chloe Villani, and the Massachusetts General Hospital has taken a lead in this arena by altering our clinical practice model to provide expert multi-disciplinary care by creating the Severe Immunotherapy Complications Service. Importantly, this group is not just involved in the clinical care but they have banded together to set up infrastructure to empower specimen collection and facilitate translational research efforts, in order to understand the mechanisms driving immune-related adverse events (irAEs). Blood/tissue samples are systematically collected in an attempt to develop better therapies to treat autoimmune toxicities while maintaining anti-tumor immunity. The hope is that this will further our understanding of early mechanisms leading to autoimmune diseases and identify novel druggable targets with immunosuppressive potential.  The Severe Immunotherapy Complications Service brings together expertise from a variety of clinical divisions and scientists across the institution to coordinate our care and tackle a critical problem facing many cancer patients today.