Problems in monitoring horizontal gene transfer in field trials of transgenic plants Heinemann, J. A. & Traavik, T. Monitoring and modeling horizontal gene transfer Nielsen, K. M. & Townsend, J. P. Nature Biotechnology September (2004) Two Perspectives articles that deal with the important issue of monitoring horizontal gene transfer.

A stepwise epigenetic process controls immunoglobulin allelic exclusion Bergman, Y. & Cedar, H. Nature Reviews Immunology October (2004)

Connecting proliferation and apoptosis in development and disease Hipfner, D. R. & Cohen, S. M. Nature Reviews Molecular Cell Biology October (2004) For tissues to grow, cells must proliferate faster than they die. The authors examine the evidence for the mechanisms that control the in vivo competition among cells for growth and survival factors.

In search of the holy replicator Gilbert, D. M. Nature Reviews Molecular Cell Biology October (2004) A timeline that looks at our current understanding of what makes up the metazoan replicator, more than 40 years after the first models were proposed.

The Knockout Mouse Project The Comprehensive Knockout Mouse Project Consortium Nature Genetics September (2004) The European dimension for the mouse genome mutagenesis program The European Mouse Mutagenesis Consortium Nature Genetics September (2004) Two commentaries on the progress of these two important community projects: a high-throughput international effort to produce and phenotype knockouts for all mouse genes, and functional annotation of the mouse genome.

Imaging gene expression in single living cells Shav-Tal, Y., Singer, R. H. & Darzaqc, X. Nature Reviews Molecular Cell Biology October (2004)

Gene therapy for autoimmune diseases: quo vadis? Chernajovsky, Y., Gould, D. J. & Podhajcer, O. L Nature Reviews Immunology October (2004) This review summarizes the ingenuity and variety of gene-therapy approaches used for the design of therapeutic molecules and vectors, the engineering of cells and the regulation of gene expression for multiple sclerosis, type-1 diabetes and rheumatoid arthritis.

DNA-microarray analysis of brain cancer: molecular classification for therapy Mischel, P. S., Cloughesy, T. F. & Nelson, S. F. Nature Reviews Neuroscience October (2004).