NKX2-1 and lung adenocarcinoma: Notably upregulated in ADCs relative to SCCs was STK11 (or LKB1), loss of which has been previously shown to induce adeno-to-squamous differentiation of lung tumors in mice [38]; GATA4 and GATA6, important for cell differentiation and commonly amplified in EAC and gastric cancers [4]; and NKX2-1, a commonly used marker for lung adenocarcinomas.