A secret unit of clone troopers operated inside the Galactic Empire's Advanced Science Division in the early years of its rule. This unit transformed the troopers into highly specialized soldiers referred to as Clone X troopers. As part of this transformation, their pasts were wiped clean, they were subjected to intense conditioning, and those who managed to live through it became fiercely devoted to the Empire. The members of this unit included Clone X, CX-1, CX-2, Sniper CloneX3, Sniper CloneX4, Sniper CloneX5, and yet another trooper. The renegade clone commando Crosshair was brought into the unit, but the training did not work on him because of his distinctive clone flaws. These Clone X troopers were put to use in Royce Hemlock's deep undercover program. Ultimately, a group of enhanced and altered clone killers, known as CX squad, was developed and sent into action during the battle on Wayland.