This article refers to:
Vol. 23, no. 14, p. 4859-4869, 2003. When our article was in print, we became aware that some properties of MAQ1, the 65-kDa protein partner of P-TEFb and 7SK RNA, had recently been reported by Ouchida and coworkers (R. Ouchida, M. Kusuhara, N. Shimizu, T. Hisada, Y. Makino, C. Morimoto, H. Handa, F. Ohsuzu, and H. Tanaka, Genes Cells 8: 95-107, 2003). Thus, to avoid confusion, it might be more appropriate to adopt the HEXIM1 nomenclature as proposed by these authors.