The film had to be bailed out by the studio's insurance company, after running over-budget and falling significantly behind schedule.
The round Sigil Tattoo seen on Vin Diesel's neck is known as "The Gate of the Necronomicon" and is protective, symbolizing Man, the Creator and The Watchers.
When the film was released, director Mathieu Kassovitz called it a "bad episode of "24" (2001)." In an interview with amctv.com, Kassovitz said that Twentieth Century Fox interfered throughout production, and he never had a chance to shoot a scene the way it was scripted, or the way he wanted it to be.
The studio apparently cut 70 minutes of Mathieu Kassovitz's original version, against his wishes, to get to a running time of 93 minutes.
The movie got almost no promotion, due to a feud between Mathieu Kassovitz and Fox studios over the final version.
Was not screened for US critics.
The film is based on a novel, Babylon Babies, by Maurice Georges Dantec.
In March 2007, the film crew in the Czech Republic took a two-week hiatus to deal with uncooperative weather, such as the lack of snow, and problems with set construction.
Vin Diesel dropped out of the lead role of Hitman (2007) to star in this movie.
French actor Vincent Cassel was initially sought to be cast in the lead role
The Cyrillic tattoo on Vin Diesel's left hand reads "SLON" ("Elephant") which stands for "Solovetsky Lager' Osobogo Naznacheniya" (Solovki Special Purpose Camp), one of the earliest GULAG's encampments (1923-1933). Later, this tattoo was popular among criminals, with a new interpretation: "Smert' Legavym Ot Nozha!" (Death for Cops From a Knife!).