In this study, we found that a high level of TS expression in human NSCLC tumours was significantly associated with a reduced tumour response and a shorter progression-free survival in 24 patients treated with pemetrexed combined with platinum agents, consistent with the previous studies of patients with breast cancer or malignant mesothelioma (Gomez et al, 2006; Righi et al, 2010). Here, TYMS is linked to non-small cell lung carcinoma.