miRTarBase is a database that curates experimentally validated microRNA-target interactions (MTIs). It contains 3576 MTIs between 657 miRNAs and 2297 target genes across 17 species. The database is manually curated by reviewing relevant literature and using text-mining techniques to select research articles related to miRNA functional studies. MTIs are validated experimentally through methods such as reporter assays, western blot, and microarray experiments. miRTarBase provides a large amount of positive samples for developing computational methods to identify MTIs. It is available online at http://miRTarBase.mbc.nctu.edu.tw/ and is frequently updated. The database contains the largest number of validated MTIs compared to other similar databases. It also provides detailed information on miRNA-target duplexes, including the location of target sites, miRNA sequences, and biological features. The database includes various web interfaces for querying and visualizing MTI data. miRTarBase also allows users to submit new MTI information for curation. The database is continuously maintained and updated. It is a valuable resource for researchers studying miRNA functions and their roles in various biological processes.miRTarBase is a database that curates experimentally validated microRNA-target interactions (MTIs). It contains 3576 MTIs between 657 miRNAs and 2297 target genes across 17 species. The database is manually curated by reviewing relevant literature and using text-mining techniques to select research articles related to miRNA functional studies. MTIs are validated experimentally through methods such as reporter assays, western blot, and microarray experiments. miRTarBase provides a large amount of positive samples for developing computational methods to identify MTIs. It is available online at http://miRTarBase.mbc.nctu.edu.tw/ and is frequently updated. The database contains the largest number of validated MTIs compared to other similar databases. It also provides detailed information on miRNA-target duplexes, including the location of target sites, miRNA sequences, and biological features. The database includes various web interfaces for querying and visualizing MTI data. miRTarBase also allows users to submit new MTI information for curation. The database is continuously maintained and updated. It is a valuable resource for researchers studying miRNA functions and their roles in various biological processes.