Cell biologists at ETH Zurich have described a new organelle present in mammalian cells that is made of rings of DNA. This “mini-organ” could potentially play a role in autoimmune diseases, and it could help researchers to understand how cell nuclei evolved. Even the remarkably familiar can sometimes yield new discoveries: researchers at ETH Zurich recently identified a previously unknown compartment in mammalian cells. They have named it the “exclusome.” It is made up of DNA rings known as plasmids. The researchers published details of their discovery in the journal Molecular Biology of the Cell on September 21, 2023. The article is titled “A Dedicated Cytoplasmic Container Collects Extra-Chromosomal DNA Away from the Mammalian Nucleus.”