The PKR interferon pathway. Sites in the pathway identified as, or postulated to be, stimulated by D-HIT expression are indicated by jagged arrows. Asterisks indicate phosphorylation. Parentheses are used for the cellular RNAs (6-16, 9-27 etc.) since work on another mRNA, 561, implies that these may not be dependent solely on interferon for activation but directly induced efficiently by dsRNA (42).