Investigators at the University of North Carolina (UNC) Lineberger Comprehensive Cancer Center have found an oral drug that mitigates the toxic effects of radiation in mice by inhibiting enzymes involved in cell division:
Several decades of work have shown that cells which are not dividing are resistant to agents that damage DNA, like radiation. Workers in the Sharpless lab were then able to show that the induction of PQ [Pharmacological Quiescence, the drug-induced cessation of cell-division] immediately before or up to 20 hours after radiation exposure were able to protect mice from a lethal dose of radiation. PQ protected all the normal cells of blood, including platelets, red cells and white cells.
(Hat tip to Nyrath.)