PRMT5 has been reported to implicate in the regulation of viral replication and pathogenesis by targeting a variety of cellular substrates and viral proteins in a methyltransferase activity-dependent manner, such as HBV replication, bovine leukemia virus (BLV) infection, the human immunodeficiency virus type-1 (HIV-1) replication, the human T-cell lymphotropic virus type-1 (HTLV-1) replication, and the mouse mammary tumor virus (MMTV) replication and RNA/DNA virus infection42-44. Here, PRMT5 is linked to deltaretrovirus infections.