RK-33 is primarily investigated for its role as a potent inhibitor of the DDX3X helicase, an enzyme involved in RNA metabolism and translation that is overexpressed in several cancer types. Its main application lies in oncology research, particularly as a radiosensitizer and anticancer agent. Studies show RK-33 enhances the effectiveness of radiation therapy in cancer cells by disrupting DNA repair mechanisms and reducing cell proliferation, especially in cancers with high DDX3X expression such as breast, lung, and head and neck cancers. In addition to its radiosensitizing properties, RK-33 has demonstrated the ability to induce cell cycle arrest and promote apoptosis in tumor cells. It is also being explored in combination therapies with other anticancer drugs to overcome resistance and improve treatment outcomes. Due to its targeted action on DDX3X, RK-33 serves as a valuable tool compound in validating DDX3X as a therapeutic target and in developing novel strategies for precision cancer treatment.