Over the past 15 years, the field of neuroimmunology has been enriched by the discovery of a large number of new antibody-associated CNS diseases that are clinically meaningful because of their frequent response to immunotherapy, and biologically interesting because they provide models of how antibodies can directly affect the brain function. Recently, we are seeing that some of these disorders can result from secondary autoimmunity triggered by treatments aimed at modifying the immunologic system, such as immune checkpoint blockers or monoclonal antibodies against regulatory T cells. This issue of Neurology ® Neuroimmunology & Neuroinflammation (N2) includes 2 new examples of primary and secondary CNS autoimmunity and studies addressing other interesting topics.