An example of this are glycoprotein C (gC)-null mutants of GaHV-2, which show increased viral replication in cultured cells, however in vivo infection required a longer incubation period to establish infection, viraemia and induction of seroconversion compared to gC-positive virus, and gC-null viruses were not transmitted horizontally [53, 54]. This evidence concerns the gene GC and infection.