When Ajax forced him to the edge, his cancer took over and started to spread everywhere. Since cancer made the cells faster in growth, this became his power. Deadpool has fast healing powers. This is the reason Ajax said he could cure him (was a lie) and why Wade went after him.

What did Ajax do to Deadpool?

Ajax tortured Killebrew at his mountain home in the Alps in order to obtain Wade's teleporter frequency; after which he teleported Wade next to a nearby cliff and sucker-punched him, sending Deadpool to his apparent death.

Is Ajax from Deadpool a mutant?

Francis Freeman, better known as Ajax, was an enemy of Deadpool. He was a British mutate whose powers allowed him to not only be impervious to pain, but have superhuman physical attributes.