Matthew Welch is a professor of Cell and Developmental Biology.  The Welch Lab research program focuses on understanding how microbial pathogens target the machinery of their host cells during infection, with the overall goals of revealing crucial mechanisms of infectious disease and uncovering fundamental cellular mechanisms of general biological importance. The tiny microbes that cause disease often colonize their larger host cells through an ability to target important cellular structures and pathways. Thus, understanding how microbes interface with and inhabit host cells is crucial for uncovering disease mechanisms. Moreover, when microbes interact with host cells, they often elicit amplified cellular responses by mimicking or manipulating host molecules which themselves are poorly understood. We can therefore use microbes as powerful tools to shed light on important yet poorly understood molecular mechanisms of host cell regulation and function. The utility of our overall approach is supported by many examples of how studying interactions between microbes and host cells has enhanced our understanding of disease processes, and has simultaneously revealed fundamental features of key cellular processes, including cytoskeleton dynamics, membrane trafficking, cell cycle control, protein recycling, and cell death.