NKX2-1 is a lineage-specific transcription factor that is frequently focally amplified in lung adenocarcinoma (PMID 17982442). NKX2-1 amplification supports a diagnosis of lung adenocarcinoma, as this event occurs rarely in other tumor types, including in lung squamous or small-cell lung cancer. NKX2-1 has been proposed to be an oncogenic "survival factor" for lung adenocarcinomas (PMID 23763999) though studies have also demonstrated tumor suppressor effects for this gene (PMID 21471965). There is no known relationship between NKX2-1 amplification and drug sensitivity.