"William Birkin injected himself with this virus and mutated."
G-virus is a special item that can be found in Resident Evil: The Umbrella Chronicles.
- Waples, Damien (2007). Chastain, Rebecca. ed. Resident Evil: The Umbrella Chronicles Prima Official Game Guide. Roseville: Prima.
- ↑ Waples, Prima Official Game Guide, p.112.