SB218078 is primarily used in biochemical research as a potent and selective inhibitor of checkpoint kinase 1 (Chk1). It is widely employed in studies focused on understanding the mechanisms of DNA damage response and cell cycle regulation. Researchers utilize SB218078 to investigate how inhibition of Chk1 affects cancer cells, particularly in sensitizing them to DNA-damaging agents like chemotherapy or radiation. This compound is also valuable in exploring the role of Chk1 in maintaining genomic stability and its potential as a therapeutic target in oncology. Additionally, SB218078 aids in studying the interplay between Chk1 and other proteins involved in cell cycle checkpoints, providing insights into novel strategies for cancer treatment.