As a writer he has worked on titles such as Incredible Hulk, Mephisto and Amazing Spider-man. As a penciller some of the comics he has contributed to include Firestorm, Avengers, Kitty Pryde and Wolverine and Secret Wars II. He has been a very prolific inker, working on many books including most of Marvel Comics' line at one point or another. Series he has worked on include Cable, Captain America, Generation X, Micronauts, Uncanny X-Men, Warlock, and X-Factor.
He was editor for Marvel through much of the 1980s, most notably presiding over Epic Comics with Archie Goodwin and editing Marvel Fanfare Vol.1 for its full ten year run. He left Marvel in 2000.