His family and friends confirmed the news on social media.

“Keith was probably the most fertile creative mind of our generation in comics.

He had an infinite number of ideas, pouring constantly out.

Many, thankfully, never saw print as wholly insane or inappropriate.

But the ones that did!”

“I told them I was sick… DeMatteis and Kevin Maguire.

Giffen’s most famous early work was on the DC sci-fi superhero comicLegion of Super-Heroes.

Needless to say, his comics work greatly influenced 21st-century superhero cinema.

Keith was one of the most brilliantly creative humans I’ve ever known,” DeMatteis wrote.

“A curmudgeon with a heart of gold.

An old, dear friend.

Tom King, one of DC’s top modern talents, called Giffen “a hero.

An artist’s artist, a writer’s writer.

A master of his craft.

A genuine, proud crank.”