Songyong is most interested in the molecular basis of the viral pathogenesis, especially virus-host interaction including host immune responses. Currently, He is studying on Rift Valley fever virus (RVFV), which is a prototypic virus of the genus Phlebovirus, family Bunyaviridae. Recently, he has generated and characterized several mutant viruses lacking one or more viral proteins (78-kDa and NSm), using a reverse genetics system of RVFV developed by our group. His studies have shown that the NSm and 78-kDa proteins of RVFV were not essential for its replication. It may suggest the possibility that any involvement these two accessory proteins have in RVFV pathogenesis is something other than virus replication itself. Therefore, He is trying to identify the functions of these uncharacterized proteins, the 78-kDa and NSm, in cell culture and in mice using several mutant viruses he has generated.