In 2007, Downey was cast as the title character in the film "Iron Man", with director Jon Favreau explaining the choice by stating: "Downey wasn't the most obvious choice, but he understood what makes the character tick. He found a lot of his own life experience in 'Tony Stark'." Favreau insisted on having Downey as he repeatedly claimed that Downey would be to "Iron Man" what Johnny Depp is to the "Pirates of the Caribbean" series: a lead actor who could both elevate the quality of the film and increase the public's interest in it. For the role Downey had to gain more than 20 pounds (9 kilograms) of muscle in five months to look like he "had the power to forge iron".