miRDB is an online resource for microRNA (miRNA) target prediction and functional annotations. The resource has been updated to include 2.1 million predicted gene targets regulated by 6709 miRNAs across five species: human, mouse, rat, dog, and chicken. A new web server interface allows users to submit their own sequences for miRNA target prediction, providing flexibility in studying custom miRNAs or target genes of interest. Additionally, miRDB has identified 568 and 452 functional miRNAs in humans and mice, respectively, through a combination of computational analyses and literature mining. These functional miRNAs are presented in the FuncMir Collection, which helps researchers focus on functionally relevant miRNAs. The web interface and backend database are hosted by a Linux server at Washington University. The updated miRDB aims to facilitate the identification of functional miRNA targets and annotations, enhancing the understanding of miRNA roles in physiological and disease processes.miRDB is an online resource for microRNA (miRNA) target prediction and functional annotations. The resource has been updated to include 2.1 million predicted gene targets regulated by 6709 miRNAs across five species: human, mouse, rat, dog, and chicken. A new web server interface allows users to submit their own sequences for miRNA target prediction, providing flexibility in studying custom miRNAs or target genes of interest. Additionally, miRDB has identified 568 and 452 functional miRNAs in humans and mice, respectively, through a combination of computational analyses and literature mining. These functional miRNAs are presented in the FuncMir Collection, which helps researchers focus on functionally relevant miRNAs. The web interface and backend database are hosted by a Linux server at Washington University. The updated miRDB aims to facilitate the identification of functional miRNA targets and annotations, enhancing the understanding of miRNA roles in physiological and disease processes.