ARS-853 is a potent and selective covalent inhibitor of the KRAS G12C mutant protein, which is commonly found in certain cancers such as non-small cell lung cancer (NSCLC), colorectal cancer, and pancreatic cancer. It works by specifically targeting the inactive, GDP-bound form of KRAS G12C, forming a covalent bond with the cysteine residue at position 12, thereby locking the protein in its inactive state and preventing downstream oncogenic signaling through the MAPK pathway. Due to its high selectivity and mechanism of action, ARS-853 is widely used in research settings to study KRAS-driven tumor biology and signaling dynamics. It serves as a critical tool compound for validating KRAS G12C as a druggable target and has contributed to the development of clinically approved KRAS G12C inhibitors like sotorasib and adagrasib. Its use in preclinical models helps assess pathway inhibition, cellular response, and potential combination therapies with other targeted agents or immunotherapies. ARS-853 is not used clinically but remains valuable in laboratory research for probing KRAS function and evaluating therapeutic strategies in cancers with this specific mutation.