Sequential Pathogenesis Model While the Drug Discovery Program offers immediate promise for new drug therapies, the Sequential Pathogenesis Model offers exciting longer term prospects as a new paradigm of disease causation and development. This model posits that macrophages - cells that are intimately and crucially involved in the body’s immune defenses to disease - become functionally modified by certain viruses (retroviruses, such as HIV) such that they begin to proliferate and actually cause disease, rather than defend against it. The specific disease triggered by this process depends on the specific gene up-regulated in the ProMac. It is believed that the Sequential Pathogenesis process, i.e. retroviral insertion-ProMac-disease, could be a process that takes several years. This means that disease-specific ProMacs might be present well before any clinical symptoms of disease are observed. For more information, contact Marla K. Johnson