The experimental approach used by Castrillo et al. . The regulation of eukaryotic growth is described in the form of a matrix, with growth rates, nutrient-limiting conditions, and cell measurements as the three axes. Yeast continuous cultures were grown at three growth rates under four different nutrient limiting conditions (glucose, ammonium, sulfate and phosphate). Transcriptome, proteome and metabolome measurements were made for each member of this matrix. Changes that correlated with growth rate under all four nutrient-limiting conditions were attributed to intrinsic growth-related processes. Relative changes in transcriptome, proteome, and a few key metabolite measurements were correlated to identify biological pathways that play a critical role in growth-rate regulation.