1. Achten, S., Behn-Krappa, A., Ricker, M., Sprengel, J., Hölker, I., Schmitz, B., Tesch, H., Diehl, V. and Doerfler, W. (1991) Patterns of DNA methylation in selected human genes in different Hodgkin’s lymphoma and leukemia cell lines and in normal human lymphocytes. Cancer Res. 51: 3702–3709.
2. Antequera, F., Boyes, J. and Bird, A. (1990) High levels of de novo methylation and altered chromatin structure of CpG islands in cell lines. Cell 62: 503–514.
3. Behn-Krappa, A., Hölker, I., Sandaradusa de Silva, U. and Doerfler, W. (1991) Patterns of DNA methylation are indistinguishable in different individuals over a wide range of human DNA sequences. Genomics 11: 1–7.
4. Brown, S. and Rastan, S. (1988) Age-related reactivation of an X linked gene close to the inactivation centre in the mouse. Genet. Res. 52: 151–154.
5. Cooney, C.A. (1993) Are somatic cells inherently deficient in methylation metabolism? A proposed mechanism for DNA methylation loss, senescence and aging. Growth, Development and Aging 57: 261–272.