The limited efficacy of current chemotherapy approaches is epitomized in metastatic NSCLC, where time to progression ranges from 5.2 to 5.5 months, with different combinations of chemotherapy, such as docetaxel plus cisplatin[32] or new compounds like pemetrexed (an inhibitor of TS and DHFR) plus cisplatin[33]. This evidence concerns the gene TYMS and non-small cell lung carcinoma.