Importantly, ReHV replication, detected as mRNA of the glycoprotein C (gC), a late viral gene, was found exclusively in the tumor-positive lungs and not in any other organs (Figure 4I–L)—i.e., tumor-negative lungs or liver and brain in mice with tumor-positive lungs—confirming and extending previous findings that the R-337 ReHV exclusively replicated in HER2-positive tumor cells. Here, GC is linked to neoplasm.