Additional information about this network, including datasets and any atlases assembled so far, can be found on our Data Portal.
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Immune cells are found throughout the body and are the primary responders to changes in our environment, from the presence of pathogens to our nutrition and even our mental state. The immune system is composed of many different cell lineages, which use innate or adaptive receptors to sense antigens or other body perturbations. The immune system includes primary immune organs, such as the thymus and bone marrow, where immunocytes differentiate; secondary immune organs like the lymph nodes and spleen, where immunocytes identify foreign molecules and initiate responses against them, then radiating and patrolling through the body. Immunocytes also reside in front line tissues such as the gut, lung, or skin, where they orchestrate a carefully controlled balance between defense against pathogens and tolerance of food or commensal microbes.