Editorial: Complement in the Development and Regeneration of the Nervous System

First Paragraph:
The complement system is an evolutionarily ancient arm of the innate immune system. It is composed of over 40 proteins, receptors and regulators that interact in a cascade manner to protect the host against pathogens (1). The soluble circulating complement proteins are mainly produced by hepatocytes. However, it is now well established that complement factors are expressed throughout the body, including in the central nervous system (CNS). In recent years, complement factors have been shown to control major aspects of CNS development, health, injury and disease (2–4). This Research Topic gathers the latest contributions to how complement factors interact with the nervous system, providing new mechanistic insight into neurodevelopment, cognitive function, myelination, and CNS infection. Review articles highlight roles for complement in development and degeneration of the visual system, and also the status of translation and clinical trials for complement-targeted therapeutics.