RESUMO
In recent years, thousands of microRNAs (miRNA) have been found in numerous species. The huge data resulting from miRNA researches are ordered in several levels including miRNA discovery, the sequence of mature and precursor miRNAs, role in diseases, pathway interaction, target validation, and prediction, etc. To prepare a simple approach to this information, numerous databases for miRNA records have been established. The selection of the correct database can be laborious and prolonged, especially for scientists who do not have experience in this field. To facilitate access to these resources, we have classified the available databases into seven categories and have described each one. The different categories of miRNA databanks contain miRNA sequence, target validation, target prediction, expression, function, role in pathways and networks, and their roles in diseases. Moreover, examples are included to describe the prototype databases for the most common applications. Hence, this review introduces available miRNA databases and presents a convenient overview of these databases that will enable researchers with different backgrounds to find suitable miRNA-related bioinformatics web tools and relevant microRNA information rapidly.