In this post-sequencing era, geneticists can focus on functional genomics an a much larger scale than ever before. One goal is the discovery and elucidation of the intricate genetic networks that co-ordinate transcriptional activation in different regulatory circuitries. High-throughput gene expression measurement using DNA arrays has thus become routine strategy. This approach, however, does not directly identify gene loci that belong to the same regulatory group; e,g,, those that are bound by a common (set of) transcription factor(s), Working in yeast, two groups have recently published an elegant method that could circumvent this problem, by combining chromatin immunoprecipitation and DNA micro-arrays.((1,2)) The method is likely to provide a powerful arrays. tool for the dissection of global regulatory networks in eukaryotic cells. (C) 2001 John Wiley & Sons, Inc.