Both plants and animals are targeted by rapidly evolving pathogens, including viruses, bacteria and fungi. Thanks to highly adaptive immune receptors, humans can mount a new antibody response towards infection or a vaccine over the course of a week. Plant immune receptors, however, do not typically change over the lifetime of an individual. Berkeley Lab scientist Daniil Prigozhin collaborated with Ksenia Krasileva from University of California, Berkeley to study plant immune receptors using pan-genome sequencing, a technique which allows them to scan all genomes for every strain in a species within a particular branch on the tree of life. Their pan-genome analysis, published recently in The Plant Cell, showed that some plant immune receptors show a surprising degree of diversity within species. In addition, it allowed them to study how innate immunity evolves, where new receptor specificities come from, and the costs associated with making new receptors, such as the potential for autoimmunity.