I'm a noob regarding this but using wiki i found this:
"It comprises seventy-three quasars, with a minimum diameter of 1.4 billion light-years, but over four billion light-years at its widest point. According to researcher and author, Roger Clowes, the existence of structures of the magnitude of large quasar clusters was believed theoretically impossible. Cosmological structures had been believed to have a size limit of approximately 1.2 billion light-years."