The only study in MPM focused on TYMS rs34743033, a tandem repeat of 28 base pairs in the 5′ UTR promoter region that changes TYMS mRNA and protein expression.18 Consistent with our results, no association of this polymorphism with treatment outcome was observed, even though both mRNA and protein expression significantly affected survival.18,27,28 Similar results were obtained in NSCLC.17,29–32. Here, TYMS is linked to non-small cell lung carcinoma.