●In control: systematic assessment of microarray performance Van Bakel, H. & Holstege, F. C. EMBO reports October (2004) This review explores different approaches for assessing the accuracy and precision of gene-expression microarrays, focusing in particular on the advantages of using external RNA controls.

●RNA and microRNAs in fragile X mental retardation Jin, P., Alisch, R. S. & Warren, S. T. Nature Cell Biology November (2004)

●Consequences of regulated pre-mRNA splicing in the immune system Lynch, K. W. Nature Reviews Immunology December (2004)

●Actin's many actions start at the genes Franke, W. W. Nature Cell Biology November (2004) Actin has a range of well-defined functions in the cytoplasm, but the idea that it is also involved in transcription in the nucleus has been controversial for some time. This News and Views article discusses the recent confirmation that β-actin is a crucial component of the RNA polymerase II-based transcription machinery.

●CpG methylator phenotype in cancer Issa, J. P. Nature Reviews Cancer December (2004) DNA methylation has a key role in the aberrant epigenetic modifications that occur in many forms of cancer. This Opinion article examines the association between the degree of methylation and the epidemiological, histological and molecular features of cancers.

●Lifespan and mitochondrial control of neurodegeneration Wright, A. L., Jacobson, S. G., Cideciyan, A. V., Roman, A. J., Shu, X., Vlachantoni, D., McInnes, R. R. & Riemersma, R. A. Nature Genetics November (2004)

●The DNA-polymerase-X family: controllers of DNA quality? Ramadan, K., Shevelev, I. & Hübscher, U. Nature Reviews Molecular Cell Biology December (2004)

●Comparative genomics: small genome, big insights Mulley, J. & Holland, P. Nature 21 October (2004) A News and Views article that looks forward to the profusion of information on genome evolution promised by the recent publication of the genome sequence of a second pufferfish species, Takifugu rubripes.

●The double-stranded RNA-binding motif: interference and much more Tian, B., Bevilacqua, P. C., Diegelman-Parente, A. & Mathews, M. B. Nature Reviews Molecular Cell Biology December (2004) Double-stranded and other RNAs interact with proteins to regulate diverse cellular processes and this interaction is crucially dependent on double-stranded RNA binding motifs (dsRBMs). This article reviews the structural features of dsRBMs and discusses the insights that these give us into double-stranded RNA function.