UCA1 and lung cancer: Based above mentioned, and as probable epigenetic mechanisms involved, it is important to discuss the overexpression and function of lncRNAs, such as UCA1 that are involved in the resistance of lung cancer cells to Gefitinib (PC9/R and H1975), as well as, in lung cancer patients with acquired resistance to EGFR-TKI therapy with deletion of exon19 and/or genetic mutation of exon21 (L858R), where UCA1 has been associated with poor progression free survival in patients free from T790M mutation status [134].