How many movies have Brendan O'Brien and Seth Rogen collaborated on?

They have worked on 4 movies together! Their first movie together was Funny People (2009) while their highest rated movie together was Teenage Mutant Ninja Turtles: Mutant Mayhem (2023). They have not worked together since Teenage Mutant Ninja Turtles: Mutant Mayhem (2023). They are most known for their comedy films together.