Genetics. In the article “Separation of killing and tumorigenic effects of an alkylating agent in mice defective in two of the DNA repair genes” by Hisaya Kawate, Kunihiko Sakumi, Teruhisa Tsuzuki, Yoko Nakatsuru, Takatoshi Ishikawa, Seiichi Takahashi, Hiroshi Takano, Tetsuo Noda, and Mutsuo Sekiguchi, which appeared in number 9, April 28, 1998, of Proc. Natl. Acad. Sci. USA (95, 5116–5120), the authors request the following correction. On page 5118, in the legend of Fig. 3, line 3, “8 weeks after this administration” should be “7 days after this administration.”