Ubiquitin ligases are enzymes that are responsible for attaching small protein molecules called ubiquitin to other proteins, targeting them for degradation by the proteasome or altering their function in various ways. This process plays a crucial role in regulating protein stability, localization, and activity within cells. Dysregulation of ubiquitin ligases has been implicated in a variety of diseases, including cancer, neurodegenerative disorders, and immune system dysfunction. Consequently, research in this area focuses on understanding the mechanisms of ubiquitin ligase action, their substrate specificity, and their potential as therapeutic targets for various diseases.