Distributions of IGR length and distances of RNAz hits to their nearest annotated CDS element in fly and human. The two curves with shaded backgrounds show the distribution of IGRs that exceed a given length D for Homo sapiens and Drosophila melanogaster, respectively. The shape of these curves is very similar. Note that, although distances D < 50 nt are omitted in the plot, all cumulative distributions of course reach 1 at D = 1. The main difference is that the IGRs in fly are on average two orders of magnitude shorter. Thick lines indicate the distribution of distances of RNAz hits that have a distance of more than D from the nearest coding sequence. In humans, this distribution is similar to the IGR distribution, shifted to the left by a factor of 3 to 4. In contrast, we observe a completely different shape in flies: A fraction of about 40% of the RNAz hits is located adjacent to the annotated genes. On the other hand, a small fraction of the RNAz hits is located further away from coding genes than expected. RNAz hits refer to the comprehensive set p > 0.5.