Prof. O’Halloran’s research interests center on the regulatory biology and chemistry of transition metal receptors involved homeostasis and oxidative stress pathways. His work focuses on the intracellular chemistry of elements essential for growth and proliferation, (i.e. zinc, copper and iron), nanoscale drug delivery mechanisms and on the mechanisms of clinically important anticancer agents that are based on arsenic, molybdenum and platinum chemistry. His discoveries have established the function and structures of two new classes of soluble receptors: metalloregulatory proteins that govern metal responsive gene expression and metallochaperone proteins that control intracellular trafficking pathways.