Seth Rogen worried about filming serious scenes in cancer movie 50/50 in case his dramatic performance came across as "false".
Seth Rogen plays the best friend of a sick man, portrayed by Joseph Gordon-Levitt, and several parts of the movie take on a somber tone.
But the Knocked Up star feared his past roles would make cinemagoers doubt his sincerity.
He tells Sky News, "The serious scenes scared me a lot more than the comedy scenes. There are some scenes that are not played for laughs... and I was much more worried about that than the comedic scenes.
"Those had a lot more potential to feel false than the funny ones."