Multimono-ubiquitin, poly-ubiquitin, and branched-ubiquitin are all synonyms for the term "multiubiquitin." All of these terms refer to the process of adding multiple ubiquitin molecules to a single target protein. Ubiquitin is a small protein found in most cells and is responsible for marking other proteins for degradation. The addition of multiple ubiquitin molecules can affect the stability, activity, and localization of the target protein. Poly-ubiquitination is thought to be involved in many cellular processes, including protein degradation, DNA repair, and signal transduction. Studying the effects of multiple ubiquitin molecules on target proteins is an active area of research in the field of cellular biology.