- Significance of DNA cross-links on 1-(4-amino-2-methylpyrimidin-5-yl)methyl-3-(2-chloroethyl)-3- nitrosourea (ACNU)-induced cytotoxicity against ACNU-sensitive and -resistant lines of 9L rat glioma cells. Kokunai, T., Tamaki, N., Matsumoto, S. J. Natl. Cancer Inst. (1987)