HDAC6-IN-9 is a selective inhibitor of histone deacetylase 6 (HDAC6), making it a valuable tool in research focused on cellular processes regulated by HDAC6, such as protein aggregation, cell motility, and microtubule dynamics. It is widely used in studies related to neurodegenerative diseases, where HDAC6 inhibition helps enhance the clearance of misfolded proteins through modulation of the aggresome pathway. This compound also shows potential in cancer research, particularly in combination therapies, where it can sensitize tumor cells to proteasome inhibitors by disrupting protein degradation mechanisms. Due to its selectivity, HDAC6-IN-9 allows researchers to target HDAC6 without broad epigenetic effects, enabling more precise investigation of HDAC6-specific pathways in disease models.