5-Methoxyuridine (Mo5U) is a purine nucleoside analog with a broad spectrum of antitumor activity, targeting malignant tumors of the inert lymphatic system and inducing apoptosis.5-Methoxyuridine's anticancer mechanism is dependent on the inhibition of DNA synthesis.5-Methoxyuridine is a purine nucleoside analog with a broad spectrum of antitumor activity, targeting malignant tumors of the inert lymphatic system and inducing apoptosis.