Cystemustine is a DNA inhibitor that induces DNA cross-linking, thereby preventing tumor cell proliferation. It exerts cytotoxic effects by disrupting the cell cycle, inducing cell redifferentiation, and altering phospholipid metabolism. Cystemustine shows high antitumor activity and a short plasma half-life in mice, influenced by the timing of administration. It is applicable in research on various malignancies, including melanoma, glioma, renal cancer, head and neck cancer, and colorectal cancer.