This special issue on yeast proteomics provides an opportunity to acknowledge Hélian Boucherie, who retired at the beginning of this year, for his contributions to 2-D gel electrophoresis and yeast proteomics. Hélian received his Ph.D. in 1979. This was followed by a post-doctoral fellowship in 1980 in the lab of Calvin McLaughlin in California, where he had his first experience with 2-D gel electrophoresis. In 1990, he became Research Director at the CNRS (Centre National de la Recherche Scientifique). He has been the head of a research team at the Institute of Biochemistry and Cellular Genetics in Bordeaux, France, where he spent his entire career dedicated to the development and applications of 2-D gels. Hélian was also President of the SFEAP (French Society of Electrophoresis and Proteomics) from 2002 to 2005. After the brilliant demonstration of 2-D gel electrophoresis technique by O'Farrell in 1975 1, the prospects seemed enormous. However, a decade later, the results were somewhat disappointing. Though the method proved successful for a variety of applications, two main difficulties hindered the wide-scale development of 2-D gels: (1) the methodology was technically demanding and confined to a few expert laboratories and (2) the approach remained limited as long as the identity of the protein spots on the maps was unknown. Much work remained to make 2-D gel technology easier and more popular. In this context, while some colleagues (Angelika Görg and collaborators) developed immobilised pH gradients, Hélian worked intensively to improve the classical pH gradient technique in gel tubes. He defined protein extraction protocols of cell extracts that avoided any trace of proteolysis. He developed his home-made electrophoresis system and after years of effort, he succeeded in establishing 2-D maps of yeast proteins of outstanding quality, resolution and reproducibility (2, see this issue). This was the situation in 1994, the year I first met Hélian. Thanks to the contribution of Hélian and the other pioneers of 2-D gels, the technique had reached the status of the only global analysis method available for functional genomics studies, since transcriptome analysis methods did not yet exist. At this time, the yeast genome sequence was not completed and the notion of functional genomics studies was still in its infancy. The concept of untargeted global approaches was not always well understood or welcome in the scientific community. Fortunately, some influential and visionary researchers, such as Piotr Slonimski and André Goffeau, actively encouraged these approaches and supported Hélian's projects. However, a major problem still hindered the wide utilisation of 2-D gels: the question of the identifications. Tirelessly, Hélian has tackled this task. All methods were welcome to identify or provide functional information about the unknown spots. He tested nearly all the possible identification methods: immunoprecipitation, co-migration, the use of deletion or overexpression mutants, as well as continuously evolving analytical techniques such as microsequencing, amino acid composition and of course mass spectrometry. Finally, he tried to characterize more and more faint spots, including invisible spots (2, see this issue). Throughout these years, the yeast protein map was continuously enriched by new identifications and was made accessible to the scientific community on a web server (Yeast Protein Map server). The aim of all this intense technical investment was to study biological questions. Of course, Hélian never forgot the biological objective. In particular, the 2-D gel approach allowed him to make remarkable contributions in the analysis of yeast adaptation to glucose exhaustion, a physiological transition called the diauxic phase. All throughout his career, Hélian devoted himself to these two areas: 2-D gels and yeast physiology. It is symbolic that Helian's final two articles, published in this issue, deal with new spot identifications for the first area 2 and half lives of yeast proteins for the second one 3. It is thus with great pleasure that I take the opportunity of this special issue on yeast proteomics, on behalf of researchers of both the yeast and of the proteomic communities, to thank Hélian for his intense participation in the yeast proteomic adventure and to wish him a happy retirement near Bordeaux. Of course Hélian was not alone in this endeavor and the strong involvement of his colleagues should also be acknowledged. More widely speaking, this tribute to Hélian's career can also be the occasion to thank all the researchers who dedicated themselves to the technical improvements that have allowed major scientific breakthroughs. As the yeast strains present on Bordeaux vineyards contain a very abundant protein (identified in his lab as alcohol dehydrogenase), one can expect that, although retired, Hélian will continue to joyfully taste some functional aspects of yeast proteomics for many years to come. Jean Labarre