Primary cilia are tiny hair-like structures expressed on the surface of eukaryotic cells. They participate in a range of processes, such as sensing the extracellular environment and regulating signalling pathways during development. Here, a functional genomic screen is presented that used RNA interference to identify human genes involved in controlling ciliogenesis. Several positive and negative ciliogenesis modulators with broad-ranging functions were found

Cancer 'chemoprevention' uses substances to reverse, suppress or prevent the initial phase of carcinogenesis or the progression of neoplastic cells to cancer cells. Here it is shown that treatment with TRAIL proteins and all-trans-retinyl acetate can cause the death, in vitro and in vivo, of premalignant cells deficient in the adenomatous polyposis coli gene. Normal cells are unaffected. Selectively eliminating premalignant tumour cells in this way is thus an effective method for chemoprevention

It has previously been shown in mice and non-human primates that systemically delivered short RNA molecules can inhibit gene expression. Here it is shown that a short interfering RNA (siRNA) can be systemically delivered, using nanoparticles, to a solid tumour in humans. The siRNA mediates cleavage of its target mRNA, thereby also reducing levels of the encoded protein. This proof-of-principle study confirms the potential of this technology for treating human disease