Mapi Garcillán-Barcia is a molecular biologist specialized in the evolution and functional genomics of bacterial plasmids. She has made foundational contributions to plasmid classification based on relaxase phylogeny and to the understanding of conjugative and mobilizable transfer systems. Her recent work advances a systems-level view of plasmid biology, incorporating evolutionary transitions between mobility states, interdependence among mobile genetic elements, and network-based horizontal gene transfer into emerging conceptual models of plasmid ecology. As leader of the Functional Plasmidomics group at the Institute of Biomedicine and Biotechnology of Cantabria (IBBTEC, CSIC–Universidad de Cantabria, Spain), she combines comparative genomics and molecular approaches to investigate how plasmid-mediated gene flow shapes bacterial adaptation. https://web.unican.es/ibbtec/r/MPilarGarcillanLAB