How does the brain take out its trash? That is the job of the brain's lymphatic drainage system, and efforts to understand how it works have pushed the boundaries of brain-imaging technologies.

Tumors, such as melanoma, release nanovesicles called exosomes (gray) that travel and lodge in the lymph nodes. There they corrupt the behavior of lymph cells. The lymphatic vessels (green) branch out ...

The lymphatic system, made up of lymphoid tissues known as nodes and vessels, is part of the human immune system. It is involved in protecting the body against infection, by delivering immune cells, ...