The series has become a linchpin that is interwoven with, and ties together, much of King's body of work. The worlds of "The Dark Tower" are in part composed of locations, characters, events and other various elements from many of King's novels and short stories. Some of the principal books that are tied to this series, or that this series references, include "It", "The Stand", "Salem's Lot", "Insomnia", "Hearts in Atlantis", "The Eyes of the Dragon", "The Shining", and "Cell". The TV miniseries "Kingdom Hospital" takes place in a world in which Nozz-A-La is the most popular beverage in the world, possibly meaning those events take place in the same universe as books 4 and 5 are set.