Boutique microarray MA plots. MA plots of the boutique data set comparing (in columns) Zipf's normalization using controls (Zipfs), Zipf's normalization using housekeepers (Zipfs HK), loess normalization using housekeepers (loess HK), raw data, and, for comparison purposes only, the standard loess normalization. Each row of plots represents one pairwise comparison, only 6 of the possible 45 pairwise comparisons of the 5 microarrays used in figure 4 are shown. The top three rows show within-array comparisons, and the bottom three rows show between-array comparisons. Lowess curves are plotted in red.