●p53: traffic cop at the crossroads of DNA repair and recombination. Sengupta, S. & Harris, C. C. Nature Reviews Molecular Cell Biology January (2005) This review discusses the evidence that the tumour-suppressor protein p53 can function as a 'cellular rheostat', modulating its function depending on the basis of the cells microenvironment.

●Multicomponent therapeutics for networked systems. Keith, C. T., Borisy, A. A. & Stockwell, B. R. Nature Reviews Drug Discovery January (2005)

●Cellular immunotherapy for viral infection after HSC transplantation. Moss, P. & Rickinson, A. Nature Reviews Immunology January (2005)

Transplantation of haematopoietic stem cells is an effective treatment for leukaemia, but requires a prolonged period of immunosuppression, increasing the risk of viral infection. Can immunotherapy help?

●RNA polymerases I and III, growth control and cancer. White, R. J. Nature Reviews Molecular Cell Biology January (2005)

It is becoming increasingly clear that tumour development is associated with changes in the transcription of polymerases I and III. Several tumour suppressors are implicated in the regulation of these processes.

●Mechanisms of disease: carcinogenesis in Barrett's esophagus. Buttar, N. S. & Wang, K. K. Nature Clinical Practice Gastroenterology and Hepatology December (2004)

It is becoming increasingly clear that tumour development is associated with changes in the transcription of polymerases I and III. Several tumour suppressors are implicated in the regulation of these processes.

●Tudor domains track down DNA breaks. Stucki, M. & Jackson S. P. Nature Cell Biology December (2004)

How do cells track down the occasional lesion among the billons of base pairs of chromosomal DNA? The Tudor domains of the DNA-damage response factor 53BP1 might hold the answer.

●Drug Insight: cancer cell immortality — telomerase as a target for novel cancer gene therapies. Keith, W. N., Bilsland, A., Hardie, M. & Evans T. R. J. Nature Clinical Practice Oncology December (2004)

What is the likelihood that telomerase will be a useful anticancer target?

●Cancer drug discovery: the wisdom of imprecision. Gudkov, A. V. Nature Medicine December (2004)

Fishing expeditions for new drugs that involve the screening of random compounds get the thumbs up in this News and Views article. Isolation of a new p53 activator shows the end justifies the imprecise means.