Recently, accumulating evidence has implicated host cell kinases as regulators of the activity of RdRp complexes of different negative-strand RNA viruses [64] : host cell kinases of the PI3K-Akt pathway manipulate paramyxovirus RdRp activity through Akt-mediated phosphorylation of the viral phosphoprotein, an essential component of the RdRp complex. Furthermore, Akt activity itself is upregulated through activation of PI3K during influenza A infection via direct interaction of the viral NS1 protein with PI3K [65, 66] . In the case of MeV, however, published data [67, 68] and our own observations (Krumm and Plemper, unpublished) demonstrate that Akt inhibition causes a moderate reduction in virus release, whereas titers of cell-associated progeny particles remain unchanged. While this rules out the PI3K-Akt pathway as a direct target for JMN3-003, it illuminates the intricate regulatory interactions between pathogen and host, which provide a wealth of possible points of entry for antiviral intervention. Future identification of the molecular target of JMN3-003 carries high potential to further our understanding of these interactions and may conceivably provide a basis for pharmacophore extraction and structure-driven scaffold optimization.