EIF4E and neoplasm: Unlike ribavirin, a broad-spectrum antiviral drug that blocks eIF4E activity through a physical mimic of the m7G cap, exhibited mild anti-tumor activity (16, 32), treatment with HHT as a single agent efficiently inhibited the growth of THP-1 leukemia cells expressing high levels of p-eIF4E, an aggressive M5 subtype of acute myeloid leukemia (AML-M5), in NSG mice and greatly increased the survival time of leukemia mice.