AUTHOR CORRECTION
Volume 29, no. 9, p. 2443-2455, 2009, https://doi.org/10.1128/MCB.01443-08. Page 2448, : The Smad2 immunoblot image for the 10 pM sample was an inadvertent duplication of the 200 pM image. The corrected image should appear as shown below. We regret this error. The correction does not affect the conclusions of the study.