Prof. István Csabai is doing research in several multidisciplinary fields where the new technologies make possible to collect and analyze large amount of data. His research focus is to understand complex systems, be it the living cell, the manmade Internet, or the large scale structure of the Universe. Complex systems can be described only by complex models, and to create and validate these models collection and analysis of huge amount of data is required. Beyond the standard domain knowledge of the traditional disciplines, methods of modern statistical analysis, data mining, machine learning and other computational techniques gain bigger and bigger role. Prof. Csabai has solid background knowledge in these topics and has experience in multidisciplinary research working together with researchers in astronomy, complex network research and genomics. In astronomy he has earned the ?builder? status in the Sloan Digital Sky Survey project, which produced the first large scale 3D map of the Universe and has created the first multi-terabyte science database and Virtual Observatory. He was part of the team that developed the database and several statistical data analysis tools. Not only Nature produces complex systems but the human society itself, too. The Internet, for example, is a complex network with complicated topology and hierarchical layers of protocols but it has no blueprint, we have to analyze it like a natural system. Building on this experience with large scientific databases and data mining technologies Prof. Csabai was part of several European ICT projects, measured and modeled the internet, social and financial networks. Genomics is one of the rapidly developing fields of sciences where the data avalanche resulting from the new sequencing equipments require the application of similar advanced statistical and informatics-heavy methods which proved to be efficient in the above mentioned areas. He has active collaborations with several national and international groups including Semmelweis University, Hungarian Academy of Sciences, Dana Farber Cancer Inst. Harvard (USA), Technical Univ. Of Denmark (Dánia), Francis Crick Institute (UK), The Johns Hopkins Univ. (USA). He got more than 32000 independent citations for the 230 scientific papers (cumulative impact factor 640) he had contributed, his Hirsch index is 75.