 While at the University of Washington, she pioneered the study of tuberculosis in zebrafish as a close approximation to tuberculosis in humans.This strategy led to a fundamental new biological understanding of how disease develops.Zebrafish larvae are optically transparent and lend themselves to genetic manipulation; by infecting them with their natural pathogen, "Mycobacterium marinum", a bacterium that causes tuberculosis in fish and is a close genetic relative of the bacteria that cause tuberculosis in humans, she could carefully track the infection while manipulating the genes of both the larvae and the bacteria.