These results revealed that ORF45 induces cell detachment, migration and invasion of KSHV-infected cells during lytic replication and promotes KSHV de novo infection and cell-contact dependent viral infection by inducing Filamin A phosphorylation, indicating that ORF45-mediated Filamin A phosphorylation plays an essential role in KSHV viral transmission and pathogenesis. The gene discussed is FLNA; the disease is infection.