Ubiquitylation is a post-translational modification process in which a small protein called ubiquitin is attached to target proteins. This modification can regulate various cellular processes such as protein degradation, signal transduction, DNA repair, and protein trafficking. Ubiquitylation is a highly dynamic and reversible process that is carried out by a series of enzymes including E1 activating enzymes, E2 conjugating enzymes, and E3 ligases. Dysregulation of ubiquitylation has been implicated in various diseases including cancer, neurodegenerative disorders, and immune disorders. Research in the field of ubiquitylation focuses on understanding the mechanisms and functions of this process and developing targeted therapies for diseases associated with its dysregulation.