XPO1 and viral infectious disease: (2021), XPO1 is a key nuclear export receptor that facilitates the transport of the viral RNA-dependent RNA polymerase (NIb) of Turnip mosaic virus (TuMV) from the nucleus—where NIb is translocated after translation and undergoes SUMOylation to promote viral infection—toward the viral replication complexes (VRCs) located in the perinuclear region.