NPM1 and viral infectious disease: Due to this ability, NPM1 has been implicated in many stages of viral infection through interaction with a multitude of proteins from heterologous viruses (Table 1), including Human immunodeficiency virus type 1 (HIV-1) Rev [4], Human T-cell leukemia virus type 1 (HTLV-1) Rex [6] and Herpes simplex virus type 1 (HSV-1) UL24 [7].