Predicts biological targets of miRNAs by searching for the presence of conserved 8mer and 7mer sites that match the seed region of each miRNA. Sites with mismatches in the seed region that are compensated by conserved 3' pairing are also identified. In mammals, predictions are ranked based on the predicted efficacy of targeting as calculated using the context scores of the sites. targetscan.Hs.eg.db provides detailed information about the latest version of the TargetScan miRNA target prediction database. This package is updated biannually.