miR2Disease is a manually curated database that provides a comprehensive resource of microRNA (miRNA) deregulation in various human diseases. The current version documents 1939 curated relationships between 299 human miRNAs and 94 human diseases, based on more than 600 published papers. Around one-seventh of these relationships represent the pathogenic roles of deregulated miRNAs in human disease. Each entry in the database includes detailed information on a miRNA-disease relationship, such as the miRNA ID, disease name, description, expression pattern, detection method, experimentally validated target genes, and literature reference. The database provides a user-friendly interface for querying entries by miRNA ID, disease name, or target gene. It also includes a submission page for researchers to submit new miRNA-disease relationships, which are reviewed and added to the database if approved. miR2Disease is freely available at http://www.miR2Disease.org. The database was developed to address the need for a centralized resource on miRNA-disease relationships, which are scattered in the literature. miR2Disease includes information on the relationships between miRNAs and various diseases, including cancer, metabolic disease, and cardiovascular disease. It also provides a bipartite network showing the causal relationships between 85 miRNAs and 32 cancer-related diseases. The database includes information on the mechanisms of miRNA deregulation in diseases, such as miRNAs located in disease-causing genomic regions, abnormal epigenetic patterns, and enzyme abnormalities involved in miRNA biogenesis. Additionally, it includes entries where genetic variations affect cellular functions through disruption of miRNA target selection. miR2Disease is a valuable resource for researchers studying the role of miRNAs in human disease. It provides a comprehensive and organized collection of miRNA-disease relationships, which can be used to understand the pathogenesis of diseases and to develop new diagnostic and therapeutic strategies. The database is updated monthly and will continue to be expanded in the future.miR2Disease is a manually curated database that provides a comprehensive resource of microRNA (miRNA) deregulation in various human diseases. The current version documents 1939 curated relationships between 299 human miRNAs and 94 human diseases, based on more than 600 published papers. Around one-seventh of these relationships represent the pathogenic roles of deregulated miRNAs in human disease. Each entry in the database includes detailed information on a miRNA-disease relationship, such as the miRNA ID, disease name, description, expression pattern, detection method, experimentally validated target genes, and literature reference. The database provides a user-friendly interface for querying entries by miRNA ID, disease name, or target gene. It also includes a submission page for researchers to submit new miRNA-disease relationships, which are reviewed and added to the database if approved. miR2Disease is freely available at http://www.miR2Disease.org. The database was developed to address the need for a centralized resource on miRNA-disease relationships, which are scattered in the literature. miR2Disease includes information on the relationships between miRNAs and various diseases, including cancer, metabolic disease, and cardiovascular disease. It also provides a bipartite network showing the causal relationships between 85 miRNAs and 32 cancer-related diseases. The database includes information on the mechanisms of miRNA deregulation in diseases, such as miRNAs located in disease-causing genomic regions, abnormal epigenetic patterns, and enzyme abnormalities involved in miRNA biogenesis. Additionally, it includes entries where genetic variations affect cellular functions through disruption of miRNA target selection. miR2Disease is a valuable resource for researchers studying the role of miRNAs in human disease. It provides a comprehensive and organized collection of miRNA-disease relationships, which can be used to understand the pathogenesis of diseases and to develop new diagnostic and therapeutic strategies. The database is updated monthly and will continue to be expanded in the future.