The Hope Serum
After coming close to successfully developing a cure for the Legacy Virus, Dr. Kavita Rao, one of the world's leading geneticists, was approached by Ord from the Breakworld with new research. Approaching mutancy and the X-Gene as a disease, Dr. Rao began her work on a mutant cure with the understanding that no one would be hurt and that this cure would help mankind.
Dr. Rao eventually developed a successful gene therapy, using the Legacy Virus cure present within a revived Colossus. The research methods and tests subjects used were not fully disclosed, but tests were performed on dead mutants' bodies. The cure, named "Hope", comes in a liquid form for intramuscular injection. A single use or injection provides permanent effects. The cure appears to suppress any effects of the X-Gene. However, it's not clear if the Hope eliminates the X-Gene, blocks the production of Mutant Growth Hormone or how the cure would effect a mutant with a physical mutation (i.e. Nightcrawler or Rockslide).
During their summer break from the Xavier Institute, the Hellions Squad came in contact with a man calling himself the Kingmaker. He offered to make their "dream come true" today in exchange for an undefined favor in the future.
Wither, a mutant with the ability to decay organic material, wanted to be able to "turn off" his powers. To solve this issue, the Kingmaker acquired an experimental sample of Benetech's Cure Mark II. This version of Hope has temporary effects and is in capsule form to be taken twice daily by mouth. It is not revealed if this new version of Hope was ever released to the general population.
During the months leading up to the return of Hope Summers, Bastion and the Human Council erected large beacons around the Bay Area to create an energy dome to cut off the X-Men from escape or help. Not knowing the true nature of these beacons, Cyclops sent the X-Club to investigate.
Once the X-Club arrived on the oil rig, Bastion activated a hologram projection of a dystopic future where Hope Summers (now Hub) had inadvertently enslaved mutantkind. In the holographic deception, a depowered Beast convinced Dr. Rao to produce one last vial of the Hope Serum to rob Hope of her powers. Realizing it was a trap, Dr. Rao instead created a pyrovirus. This revealed Bastion's plans, and the X-Club was able to escape. Rao then let the formula, coded in her bracelet, fall in San Francisco Bay.
Dr. Amara Perera's cure for the mutant gene
Dr. Amara Perera, a Sri Lankan biophysicist had come up with a cure for the mutant gene, but hasn't even dared to create it due to the political and sociological aftermaths that would surely occur if she did.
Ultimate Universe (Earth-1610)
It was a virus with low-intensity symptoms, inoculated to several people send to travel, in order to spread it. It function was to prevent the contraction of the X-Gene, which itself originates from a virus, and in essence wipeout the the human mutant genome.
X-Men Cinematic Universe (Earth-10005)
The Mutant Cure was synthesized from a mutant, Leech, and was developed by Dr. Kavita Rao in Worthington Labs on Alcatraz. The cure was released to willing mutants, and also militarized into a weapon. The effects of this cure appear to be somewhat temporary. It was this that motivated Magneto to lead his Brotherhood of Mutants to overtaken Alcatraz and destroy The Cure. To accomplish this moved the entire Golden Gate Bridge as passage to for his army.
Age of X (Earth-11326)
The Cure was developed by Dr. Richard Palance and Dr. Kavita Rao. Palance intended to use it on large scale, while Rao intended to use it on mutants who wanted to voluntarily deactivate their powers. Rao learned about Palance's true intentions when Wolverine broke into her office with the intent of ending their work. Rao managed to destroy the only viable specimen by metabolizing it into Wolverine's body. He was able to to survive the overdose of the cure thanks to his regenerative healing factor. However, the cure was effective in nearly robbing Logan of his powers. His healing factor was reduced to merely preventing his death from Adamantium poisoning.
- Beast has the only remaining vial of Hope Serum.
- Dr. Kavita Rao once carried the formula to the Hope Serum written on her bracelet. However, she purposely disposed of it in the San Francisco Bay.