Deadline is reporting that Christina Applegate is leaving the NBC comedy "Up All Night." Applegate starred in the show alongside Will Arnett as new parents coping with parenthood. "It's been a great experience working on 'Up All Night,' but the show has taken a different creative direction and I decided it was best for me to move on to other endeavors," Applegate told Deadline. The show was in the process of being totally revamped. Applegate is set to reprise her roll in the upcoming "Anchorman" sequel, which starts to film in February.