SEC inhibitor KL-2 is primarily used in research settings to study the mechanisms of protein secretion and translocation within cells. It is particularly valuable in understanding the Sec61 translocon complex, which plays a critical role in protein transport across the endoplasmic reticulum membrane. By inhibiting this pathway, researchers can investigate the effects of disrupted protein secretion on cellular function and disease processes, such as cancer and neurodegenerative disorders. Additionally, it serves as a tool to explore potential therapeutic targets for conditions linked to defective protein trafficking. Its application extends to drug development studies, where it helps in identifying molecules that can modulate protein secretion pathways for therapeutic purposes.