CSF2 and neoplasm: (i) GM-CSF (Granulocyte-Macrophage Colony-Stimulating Factor) enhances anti-tumor immune responses by recruiting and activating immune cells, (ii) Deletion of ICP34.5 (γ34.5), a virulence factor that inhibits the host PKR antiviral pathway, increases viral selectivity for cancer cells with defective PKR signaling.