H-89 is widely utilized in biochemical research due to its role as a potent and selective inhibitor of protein kinase A (PKA). It is particularly valuable in studies aimed at understanding the signaling pathways and cellular processes regulated by PKA. Researchers employ H-89 to investigate the effects of PKA inhibition on various physiological functions, including cell proliferation, differentiation, and metabolism. Additionally, it is used in neuroscience to explore the involvement of PKA in neuronal signaling and synaptic plasticity. H-89 also finds application in pharmacological studies, where it helps in identifying potential therapeutic targets by elucidating the role of PKA in disease mechanisms. Its ability to selectively inhibit PKA makes it a crucial tool in dissecting complex signaling networks and understanding the molecular basis of PKA-mediated cellular responses.