These miRNA target predictions are regularly updated and improved by the laboratory of David Bartel in conjunction with the Whitehead Institute Bioinformatics and Research Computing Group.
[citation needed] TargetScan includes TargetScanHuman,[2][3][4][5][6] TargetScanMouse,[2][3][4][5][6] TargetScanFish,[6][7] TargetScanFly,[8][9] and TargetScanWorm.
TargetScan provides accurate rankings of the predicted targets for each miRNA.
[6] These rankings are based on either the probability of evolutionarily conserved targeting (PCT scores.
In particular, TargetScanWorm and TargetScanFish are based on C. elegans and zebrafish mRNA models for which 3' untranslated regions (3' UTRs) are defined using polyadenylation sites that are experimentally determined using accurate high-throughput methods.