AZD-6738 is primarily used in the field of cancer research and treatment. It functions as an inhibitor of the ATR kinase, which plays a crucial role in the DNA damage response. By targeting ATR, AZD-6738 disrupts the ability of cancer cells to repair DNA damage, leading to cell death. This makes it particularly effective in cancers with high levels of replication stress or those that have defects in other DNA repair pathways, such as BRCA mutations. It is often studied in combination with other therapies, such as chemotherapy or radiation, to enhance their effectiveness. Clinical trials are ongoing to evaluate its potential in treating various types of cancer, including solid tumors and hematologic malignancies.