RETRACTION
Volume 189, no. 13, p. 4964–4968, 2007, https://doi.org/10.1128/JB.00310-07. There were errors in the construction of Fig. 2B and 4C, where the incorrect panels were used to represent Xcc 8004 and Xcc ΔrpfF and S. maltophilia K279a rpfF with added diffusible signal factor (DSF). We apologize for these errors and retract this article due to this data misrepresentation. The corresponding author (J. M. Dow) takes responsibility for these errors.