TYMS and neoplasm: Our data shows that TYMS overexpression increased 3-fold the mean tail moment in hTS5278 (77.36, n = 15) compared to 5318 control cells (21.67, n = 20) (Fig. 5C), confirming that overexpression of TYMS in Ink4a/Arf−/− tumor cells contributes to a statistically significant increase (P = 0.0012) in double strand DNA damage.