In season 10 episode 3, Mulder is shown reading over old archives while throwing pencils into this poster. Scully walks in and exclaims "Mulder! What are you doing to my poster?!".

This highlights how Mulder becomes increasingly disillusioned with his life long obsession, as he has recently learned that his sister was just part of a government experiment, meanwhile Scully always humored him but is now taking on more the Mulder role as she seeks answers to the origin of her child and own abduction.