Establishing the first connection between Deadpool and Wolverine, the latter's DNA was placed inside Wilson, allowing his regenerative healing factor to emerge. While Deadpool operated without scars for a short time, his healing factor began to react to his cancer, causing scarring akin to his live-action adaptations.
It has been revealed that at the time his healing ability was given to him, Deadpool suffered from some form of cancer; after the healing factor was given to him, it made his normal cells as well as his cancerous cells unable to die, giving him a heavily scarred appearance beneath his suit.
These "super-cancer" cells persistently destroy his healthy cells while his healing abilities rapidly regenerate them. This endless conflict between the healing factor and the cancer cells results in Wilson's disfigured appearance. His inability to heal his skin lies in his failure to cure his cancer.
Wade accepted and was granted a superhuman healing factor, but his face and body became permanently disfigured (both physically and mentally) as a result. Still, he survived the experiment and was inducted into the Weapon X program, a covert ops unit composed of other superpowered beings.
In the film, Reynolds' character Wade Winston Wilson, known as Deadpool, is diagnosed with cancer in his liver, lungs, prostate and brain. In a short clip posted online in 2016, Reynolds-as-Deadpool says testicular cancer is the most common cancer for men aged between 15 and 35 and urges men to “fight back”.
Wade Becomes Deadpool - Wade Wilson Mutation Scene - Deadpool (2016) Movie CLIP HD
Why doesn't Deadpool's cancer heal?
This question is answered by the fact that Deadpool's cancer hasn't actually been cured but simply put on pause, meaning it is constantly battling with his healing factor, causing his severe disfigurement, which will assumedly still be in place when Deadpool joins the MCU in Phase 5.
In Deadpool Annual 2013, Deadpool is ripped apart by Luke Cage and Thor. He's split straight down the middle, but he had been melded together with Madcap for the duration of the issue, so the two halves simply become each of them. Since there was no technical injury, the two guys come out unscathed and fully formed.
Deadpool's immortality lies in his cancer and regeneration ability. According to the comics, cancer triggered his healing powers. As a result, the cancerous cells regenerate just like the normal, healthy ones do.
There's a reason for that. The Merc with the Mouth has an advanced healing factor derived from Wolverine's powers, but that's where those similarities end. When William Stryker pooled a bunch of mutants' powers into Wade Wilson in X-Men Origins: Wolverine, he went ahead and gave Deadpool an adamantium skeleton.
Along with his extra mutant powers, one of the things Stryker did to Wilson was have his mouth surgically shut, making him the perfect soldier in Stryker's eyes. In the post-credits scene his mouth is partially open.
Yes, Deadpool feels every bit of pain as normal humans do. However, his regenerative ability allows him to heal from all injuries. While Deadpool can heal quickly, he isn't indestructible. His body restores, but he does endure pain as much as a regular human would upon a similar injury.
He is supposedly killed by Victor Creed, but is later revealed to have been transformed by Major Stryker into a mutant killer "Weapon XI", who possessed other mutants' powers. His former teammates Logan and Creed fight Weapon XI and manage to defeat and seemingly kill him.
While Wade does get inebriated if he drinks a lot of alcohol, his body's super-powerful immune system protects him from getting drunk easily, meaning that Wilson needs a lot of alcohol in his system before he can even remotely be affected.
Training: He has been highly trained in swordsmanship, marksmanship, strategic/tactical planning, assassination aptitude and martial arts by Nick Fury himself as well several other master combatants.
Deadpool and Wolverine boast god-tier healing factors that effectively make them immortal, as no matter the severity of the injuries they suffer, both Wade Wilson and James “Logan” Howlett are able to bounce back almost immediately.
With an insanely powerful healing factor and stubborn refusal to die, Deadpool is widely known as one of Marvel Comics' most unkillable heroes. He's been shot, stabbed, blown up, and dismembered, but Wade Wilson always comes back.
As Deadpool/Captain Universe exit Eternity, he continues to beat Thanos until he explodes into a blast of cosmic energy. Considering the Marvel Comics are filled with alternate timelines and multiverses, it's no surprise that Deadpool is able to kill Thanos twice.
Extended Lifespan - It is unknown how long Deadpool will live but it has been shown to be further than 800 years into the future, it is believed he is unable to die as he has established a romantic like relationship with the personification of Death.
Yes, Deadpool feels every bit of pain as normal humans do. However, his regenerative ability allows him to heal from all injuries. While Deadpool can heal quickly, he isn't indestructible.
So, Deadpool's main superpower is his healing factor, and what a healing factor it is. In multiple comics over the years, it's been established that Deadpool's healing factor is more powerful than Wolverine's. Deadpool can survive anything. If his head is cut off, he'll regrow his body over a few weeks.
Readers witnessed Wade Wilson's rapid regeneration abilities and Rogue's absorption powers work together at an unbelievable level, saving Rogue's life – and proving Deadpool can survive a nuclear blast.
Eventually, Wade gets out from under Stryfe's thumb, but the real miracle is that Deadpool survives the freezer in the first place, whether he is left insane or not.
