TYMS and cancer: It is targeted by chemotherapeutic drugs, like pemetrexed, in NSCLC, and has been widely studied as a chemoresistance marker.10 Our lab recently showed a correlation between TS expression and EMT markers in NCI-60 panel of cancer cell lines originating from different tissues11 and established its role in maintaining the de-differentiated mesenchymal-like state of triple-negative breast cancer.12 In this study we present evidence that TS is not a mere proliferation marker in NSCLC, but also has a direct role in driving EMT phenotypes, with several biological and clinical implications.