Used primarily in scientific research to study calcium signaling pathways, KN-62 acts as a selective inhibitor of Ca²⁺/calmodulin-dependent protein kinase II (CaMKII). This makes it a valuable tool in neuroscience and cell biology for investigating the role of CaMKII in synaptic plasticity, memory formation, and neuronal excitability. Researchers also use KN-62 to explore its effects on inflammatory responses and immune cell function, as CaMKII is involved in signaling pathways related to inflammation. Its application is largely restricted to in vitro studies due to limitations in solubility and in vivo stability.