KN-93 hydrochloride is widely used in research settings as a potent and selective inhibitor of calcium/calmodulin-dependent protein kinase II (CaMKII). Its primary application is in studying the role of CaMKII in various cellular processes, particularly in neuroscience and cardiovascular research. It helps researchers understand the involvement of CaMKII in synaptic plasticity, learning, memory, and cardiac function. Additionally, KN-93 hydrochloride is utilized to investigate the signaling pathways associated with CaMKII in diseases such as arrhythmias, heart failure, and neurodegenerative disorders. Its inhibitory effects make it a valuable tool for dissecting the molecular mechanisms underlying these conditions.