DNA arrays have opened the door to comparative studies of gene expression on a massively parallel scale. Unfortunately, similar tools for analyzing the proteins on such a global scale are not yet available. In a recent issue of Proc. Natl. Acad. Sci USA (96, 10632–10636, 1999), David Morris and his colleagues have devised a compromise solution to this problem: use DNA arrays to identify those mRNAs undergoing active translation. Using a method called sucrose gradient analysis, populations of cellular mRNAs that are either rapidly or poorly translated are isolated from both quiescent and actively growing cells. DNA probes made from these pools are then applied to commercially available cDNA arrays. About 1% of the mRNAs were found to be translationally regulated in fibroblasts stimulated with growth factors. "From our standpoint, the real advance of this work is making it easier to look at phenotype", states Morris. He points out that although DNA array technologies still have difficulty detecting very low-level messages, the approach his group has devised is still more sensitive than protein analysis on two-dimensional gels.