Further, sample grouping based on the TNM classification (Sobin et al, 2009) revealed that the Em/Ad expression ratios increased to 2.23 (P = 4.6E‐10) for GATA6 and 1.67 (P = 6.3E‐3) for NKX2‐1 at stage I (Fig 1D and Table EV2), supporting the use of increased Em/Ad of GATA6 and NKX2‐1 as biomarkers for detection of early staged LC. This evidence concerns the gene NKX2-1 and laryngotracheoesophageal cleft.