While previous studies failed to find an association between TS expression genotypes and pemetrexed efficacy in advanced NSCLC [38], the authors found that in their study median PFS was longer (6.8 versus 3.8 months, P = 0.036) for patients with the “low-expressing” polymorphisms (2R/2R, 2R/3C, or 3C/3C) as opposed to the “high-expressing” polymorphisms (2R/3G, 3C/3G, or 3G/3G). Here, TYMS is linked to non-small cell lung carcinoma.