The sequence at specific positions in the early transcribed region sets the rate of transcript synthesis by RNA polymerase II in vitro.
Weaver JR, Kugel JF, Goodrich JA. The sequence at specific positions in the early transcribed region sets the rate of transcript synthesis by RNA polymerase II in vitro. J Biol Chem. 2005 Dec 02; 280(48):39860-9.