EIF2AK2 and cancer: A variety of signaling pathways usually involved in viral clearance, including IFN (interferon), TLR (Toll-like receptors), JAK–STAT (Janus kinase–signal transducer and activator of transcription), and PKR (double-stranded RNA-activated protein kinase) pathways, may be deficient or inhibited in cancer cells, allowing OVs to enter and survive in these cells (26–28).