MG-132 solution is widely used in biomedical research as a potent and reversible inhibitor of the proteasome, a cellular complex responsible for degrading damaged or unwanted proteins. By inhibiting the proteasome, MG-132 helps researchers study protein degradation pathways and the role of the ubiquitin-proteasome system in various cellular processes. It is commonly applied in studies involving apoptosis, cell cycle regulation, inflammation, and signal transduction, particularly the NF-κB pathway, which is sensitive to proteasome inhibition. MG-132 is also used to induce endoplasmic reticulum (ER) stress and to investigate mechanisms of neurodegenerative diseases, where protein aggregation and impaired degradation play key roles. Due to its cell-permeable nature, MG-132 is effective in both in vitro cell culture models and certain ex vivo experimental systems. However, it is not used therapeutically due to its toxicity and instability in vivo. Its primary value lies in its utility as a research tool for understanding protein homeostasis and disease mechanisms.