former was significantly left-shifted, indicating that the observed down-regulation is largely specific to the targeted genes (Figure 1C, middle panel). For each targeted gene, we computed the rank of its z-score in the experiment in which it was targeted relative to all other experiments in the dataset where it was not targeted. We observe that 841 of 955 genes (88%) rank in the top 1% and 907 of 955 (95%) rank in the top 5% (Figure 1C, bottom panel). These results indicate that the large majority of L1000 probes are specifically measured.
