Studies at Emory have shown that certain viruses, including those from the Poxviridae family, use Abl- and Src-family tyrosine kinases for actin motility, but that the release of virions requires Abl- but not Src-family tyrosine kinases. Inhibitors of Abl-kinases, such as the known anticancer agent imatinib, sold under the tradename Gleevec®, can block the release of Poxviridae virions from the cell. Preclinical studies have shown that imatinib reduces viral dissemination by five orders of magnitude and promotes survival in infected mice, suggesting use for this drug in treating microbial infections that rely on host tyrosine kinases such as smallpox or complications associated with vaccination. Because the drug targets host but not viral molecules, this strategy is much less likely to engender resistance compared to conventional antimicrobial therapies. Based on this technology, Inhibikase Therapeutics is developing certain tyrosine kinases, for treatment of infectious disorders. In 2011, Inhibikase obtained approval to enter phase II clinical studies for treatment of progressive multifocal leukoencephalopathy in patients that are taking Tysabri®.