Tuberculosis (TB) is currently the world’s leading cause of mortality due to a single infectious agent. It has been estimated that approximately one-third of the world’s population is infected with Mycobacterium tuberculosis, the bacteria that causes TB. Approximately two million people die of TB annually, and about eight million new cases arise each year. In addition to the emergence of multi-drug resistant strains of the disease, TB develops much more readily in people with HIV infection, and is a leading cause of AIDS-related death. There is an urgent need for novel therapeutics and drug targets in order to control the global spread of TB. In order to evade attack by the host immune system, M. tuberculosis secretes a protein called Protein tyrosine phosphatase A (PtpA). PtpA interacts with multiple proteins in the host that are normally essential for the destruction of bacterial pathogens. However, the exact role of these interactions in relation to the survival of M. tuberculosis within cells is not yet completely understood. Dennis Wong is defining the role of TB-Host interactions and identifying the molecular events that are disrupted by PtpA to promote TB infection. Understanding the mechanisms by which PtpA promotes the survival of M. tuberculosis will provide important insights regarding the pathogenesis of TB and the response of the host immune system to infections. As PtpA is a potential drug target, the new knowledge may contribute to the development of novel therapeutics against one of the deadliest diseases in the world.