—Professor X[source]We're not here for your apologies. The device you created not only cloaks the mutant gene...it can also cut the gene off, denying mutants their abilities. ...You crossed a line, Reed. Against your son. Against all mutants.
The Code-X was a device created by Mister Fantastic to prevent his son from accessing the Krakoan Gateways by cloaking his X-Gene.[1]
History
When Professor X revealed Krakoa to the world and invited all mutants to the island nation, Mister Fantastic began to worry about his son, Franklin Richards. To "protect" his son and prevent him from accessing the Krakoan Gateways, Mister Fantastic created the Code-X to cloak the X-Gene.[2]
When Kitty Pryde and the X-Men arrived at 4 Yancy Street to formally invite Franklin to Krakoa, a fight broke out. However, Franklin wanted to visit Krakoa and tried to enter the Krakoan Gateway in Washington Square Park, but the Code-X prevented his entry.[3]
After peace was declared between the X-Men and the Fantastic Four, Professor X and Magneto visited Mister Fantastic to destroy the Code-X and psychically prevent him from ever being capable of rebuilding the device, since it didn't just cloak the genes, but canceled them overall.[2]Trivia
- Code-X is a phrase that appeared before in X-Statix #1 to describe mutants whose X-Gene activation made them mentally unstable.