Dr. Paulmurugan's laboratory's main goal is to develop in vivo imaging strategies for studying cellular signal transduction pathways. Signal transduction is a regulated biochemical process by which cells convert extracellular stimuli to functional changes. These pathways involve many proteins, nucleic acids, small molecule ligands, and other physical agents present within the cells and in the extracellular matrix. Signal transduction is crucial for maintaining cells in their normal functional state. They are specifically studying the signal transduction pathways involved in estrogen receptor-hormone interactions and their role in the pathogenesis of breast cancers. They are also investigating the estrogen-independent mechanisms involved in the development, progression, and metastasis of breast cancers that are negative for estrogen receptor expression. In addition, they are examining how different epigenetic processes are involved in the development of resistance to antiestrogen therapy in breast cancers. They study these processes both in cells and in living animals using advanced molecular imaging techniques.