Properties of Argonaute interaction site generation and their comparison to crosslink-centered regions. (a) Distribution of interaction site sizes for the Argonaute dataset for sites that fall within 3' UTRs and contain two or more T = > C conversion locations. The vertical red line represents the 41-nucleotide size of the Hafner et al.  crosslink-centered regions (CCRs). (b) Distribution of interaction site locations across a normalized 3' UTR for all clusters that have two or more T = > C conversion locations. (c) The signal-to-noise for the top 20 expressed miRNAs in the Argonaute dataset for both PARalyzer generated interaction sites and the Hafner et al.  CCRs located in 3' UTRs. (d) Average log2 signal-to-noise ratio of window size 21 across all 361 miRNAs reported expressed in Hafner et al. in the order of their expression rank.