In the first level you have the ability to flank some CELL soldiers by entering a small sewer after the subway. You should find some electrical wires hanging above your head that say "Caution 1.21 Gigawatts." This is a reference the the movie trilogy Back to the Future where the time machine, made from a DeLorean, needs 1.21 gigawatts of electricity to travel through time. The correct pronunciation is "gigawatts," however, they say "jigawatts" in the movie. Supposedly a scientist the movie team hired said it this way.