Distribution of hybridization values from the data points taken from Figure 1. (a) Histogram of the direct hybridization values. The curve is the best approach to a normal distribution that fits the histogram (note the poor fit). (b) Histogram of the logarithm of the hybridization values. Note that the normal distribution exhibits a much better fit (the excess of points at the low end of the curve corresponds to the excess of blank points in Figure 1, which show the background level of the hybridization signal). Note that this behavior should be verified before any interpretation of transcriptome data.