Although there were many later attempts to recreate or reverse-engineer Project: Rebirth's Super-Soldier Serum, none are known to have been involved with Weapon Plus except for the attempt that resulted in the creation of Isaiah Bradley's son Josiah X. Weapon Plus considers Captain America as its most successful creation, despite the fact that Rogers has been at odds with the United States government a number of times. Project: Rebirth was retroactively made a part of the Weapon Plus after WWII when Weapon Plus was actually formed.