I read King and Koontz during my teens, my two favourite books of each author are 'It' by King and 'Phantoms' by Koontz, I actually read 'It' first and thought Koontz had been inspired by King given how they were quite similar, however I learned later that Koontz Phantoms was published in 1983, while It was published in 1986, so I guess that if anyone was inspired by the other it was King.