WNT3A and infection: Finally, in order to determine whether or not preactivation of Wnt signaling would enhance infection with fully virulent wild-type RVFV, HeLa cells were pretreated with Wnt3A for 20 h prior to mock infection or infection with wild-type RVFV strain ZH-501 (MOI of 0.1), and the extent of infection was quantified by plaque assay of the supernatants collected from virus-infected cells.