Marvel Comics is one of the two largest American companies in comic book and related media publishing (the other being DC Comics). In 2009, The Walt Disney Company acquired Marvel Entertainment, Marvel Worldwide's parent company, for $4.24 billion. Marvel started in 1939 as Timely Publications, and by the early 1950s had generally become known as Atlas Comics. Marvel's modern incarnation dates from 1961, the year that the company launched Fantastic Four and other superhero titles created by Stan Lee, Jack Kirby, Steve Ditko, and others. Marvel counts among its characters such well-known properties as Spider-Man, the X-Men, Iron Man, the Hulk, Avengers, Fantastic Four, Wolverine, Thor and Captain America; antagonists such as Doctor Doom, the Green Goblin, Magneto, Galactus, Loki, and the Red Skull. Most of Marvel's fictional characters operate in a single reality known as the Marvel Universe, with locations that mirror real-life cities such as New York, Los Angeles and Chicago.