Commentary. In the article “Lignification of plant cell walls: Impact of genetic manipulation” by Hans-Joachim G. Jung and Weiting Ni, which appeared in number 22, October 27, 1998, of Proc. Natl. Acad. Sci. USA (95, 12742–12743), the authors request that the following corrections be noted. It was accidentally stated that the studies by Kajita et al. (1) and Lee et al. (2) dealt with cinnamoyl-CoA reductase modified plants when in fact they concerned 4-coumarate:coenzyme A ligase (4CL) transgenic plants. Lignin concentration was reduced by down-regulation of 4CL activity in both studies (1, 2). In a subsequent article, Kajita et al. (3) reported a negligible decrease in lignin concentration and a decreased syringyl-to-guaiacyl ratio for lignin composition of a sense-suppressed 4CL transgenic tobacco line. Kajita et al. (1) rather than Kajita et al. (3) was inadvertently cited when this later report was contrasted with the large decreases in lignin concentration and an increased syringyl-to-guaiacyl lignin ratio for anti-sense suppressed 4CL Arabidopsis transgenics (2). The authors apologize for the confusion these errors have created for readers of their Commentary and to the authors of the cited work for misrepresenting their research.