||Overall, researchers observe a significant relationship between mRNA levels, as measured by an earlier microarray analysis of log-phase yeast (ref 25), and protein levels (Spearman rank correlation coefficient rs = 0.57). Very abundant mRNAs generally encode for abundant proteins, and the average protein per mRNA ratio remains remarkably constant throughout the full range of mRNA abundances (Fig. 4c, middle, and Supplementary Fig. S4). The average protein per mRNA ratio is 4,800 using this measure of mRNA levels, and is 4,200 using an alternative mRNA abundance measurement based on a microarray analysis comparing mRNA to genomic DNA levels (ref 26) (Supplementary Fig. S4). Note: a comparison of median protein abundance of 2460 copies/cell (BNID 100208) and median mRNA abundance of 1.2 copies/cell (BNID 100204)gives an mRNA/protein ratio greater by a factor of 2. Table link: More than 3000 protein levels. This table is the Supplemental Data from the reference. The proteins are ordered by gene name, but could be sorted based on abundance using the function on Excel.