NKX2-1 and lung cancer: Previous studies further verified this hypothesis that Nkx2.1 gene prominent amplification in primary lung cancer tissue samples, highly suggested that the reactivation of Nkx2.1 has a close association with the initiation stage of lung cancer [9,10,11], Regulated by the TGF-β signaling pathway, Nkx2.1 is a homeodomain-containing transcription factor, solely encoded by Nkx2.1 gene belonging to the Nkx superfamily.