However, Phuchareon et al. recently identified the down-regulation of DUSP6/MKP-3 as a contributing factor to the reactivation of Ras-ERK signalling and drug resistance in epidermal growth factor receptor (EGFR) mutant lung cancer cell lines exposed to the TKI's gefitinib (Iressa) and erlotinib (Tarceva) [169]. The gene discussed is MAPK1; the disease is lung cancer.