Tubastatin A HCl is primarily used in research settings as a selective inhibitor of histone deacetylase 6 (HDAC6). It is particularly valuable in studying the role of HDAC6 in various cellular processes, such as cell motility, protein degradation, and stress response. Researchers utilize it to explore its potential therapeutic effects in neurodegenerative diseases, including Alzheimer's and Parkinson's, due to its ability to modulate tau protein aggregation and improve neuronal health. Additionally, it is investigated in cancer research for its role in inhibiting tumor growth and metastasis by targeting HDAC6-mediated pathways. Its application extends to inflammation studies, where it helps in understanding HDAC6's involvement in immune regulation and inflammatory responses.