Unlike the Ultimate Universe version of the character, Iron Man's identity was not a matter of public record, and he was inflicted with a heart condition instead of a brain tumor. Iron Man initially declined joining the Avengers, as he is accustomed to working alone, but he would eventually join the team. During the Avengers first mission, Iron Man is wounded and begins to suffocate under his mask. Captain America removes it to reveal his true identity. Iron Man helps the Avengers during the Chitauri attack and the Hulk's rampage.