MRT68921 is primarily used in biomedical research as a potent and selective inhibitor of the ULK1 kinase, a key protein involved in the initiation of autophagy. It is widely applied in studies exploring autophagy pathways, particularly in cancer research where modulation of autophagy can influence tumor cell survival and death. By blocking ULK1 activity, MRT68921 helps researchers dissect the role of autophagy in cellular responses to stress, nutrient deprivation, and chemotherapy. It has also been used in combination with other anticancer agents to assess synergistic effects, especially in models of melanoma and other solid tumors. Its selectivity makes it a valuable tool for probing kinase signaling networks without significant off-target effects at commonly used concentrations.