miRDB is an online database for predicting functional microRNA (miRNA) targets. It provides updated transcriptome-wide target prediction data for 7000 miRNAs across five species, including 3.5 million predicted targets. The database has been updated with a new algorithm, MirTarget, which improves the accuracy of miRNA target prediction. This algorithm integrates miRNA binding and target expression data to identify significant targeting features. miRDB now allows users to predict miRNA targets in specific cell models and to perform integrative analysis of target prediction and Gene Ontology (GO) data to predict miRNA functions. The database also hosts expression profiles of over 1000 cell lines, enabling researchers to analyze miRNA target expression in specific cell models. Additionally, a new web query interface has been added for miRNA function prediction by integrating target prediction and GO data. All data in miRDB are freely accessible at http://mirdb.org. The database has been updated to include new features such as custom target prediction, cell-specific target prediction, and miRNA function prediction through integrative analysis. These updates enhance the ability of researchers to identify relevant miRNA functions in specific experimental systems. The database is supported by the National Institutes of Health and is freely accessible.miRDB is an online database for predicting functional microRNA (miRNA) targets. It provides updated transcriptome-wide target prediction data for 7000 miRNAs across five species, including 3.5 million predicted targets. The database has been updated with a new algorithm, MirTarget, which improves the accuracy of miRNA target prediction. This algorithm integrates miRNA binding and target expression data to identify significant targeting features. miRDB now allows users to predict miRNA targets in specific cell models and to perform integrative analysis of target prediction and Gene Ontology (GO) data to predict miRNA functions. The database also hosts expression profiles of over 1000 cell lines, enabling researchers to analyze miRNA target expression in specific cell models. Additionally, a new web query interface has been added for miRNA function prediction by integrating target prediction and GO data. All data in miRDB are freely accessible at http://mirdb.org. The database has been updated to include new features such as custom target prediction, cell-specific target prediction, and miRNA function prediction through integrative analysis. These updates enhance the ability of researchers to identify relevant miRNA functions in specific experimental systems. The database is supported by the National Institutes of Health and is freely accessible.