Regine Kahmann is a microbial geneticist who studies plant pathogenic fungi. Her research uses the biotrophic corn smut fungus Ustilago maydis as a model to uncover basic molecular principles of plant diseases. A present focus of her work concerns secreted protein effectors: how they evolved, how they are delivered into host cells, how they downregulate plant defense responses, and how modulate the host metabolism to benefit the pathogen.