ISG15 and HIV infectious disease: Seven of these 13 genes (IFI27, IFI6, IFIT1, ISG15, RSAD2, MX1, and OAS1) are members of the Gene Ontology biological process “type I IFN signaling pathway”; four of the other 6 are known to be induced by type I IFN (DDX60, SAMD9, IFI27L1 and HERC6). Thus, drugs from the NRTI class, which are mainstay ART components, may play a role in the persistent and largely unexplained immune activation seen in PLH whose HIV infection is otherwise well-controlled.