Identifyingthe structural determinants of cathepsin S specificitymay allow for the development of compartment-specific inhibitors.While cathepsin S has been identified as a therapeutic target forautoimmune diseases and cancers, efforts to treat these diseases withcathepsin S inhibitors have not been successful.−,  If the structure of cathepsin S changes with the environment, inhibitorscould be developed that are targeted more precisely to the form ofcathepsin S in the compartments where it is contributing to pathologyand damage. The gene discussed is CTSS; the disease is cancer.