Epi proLung is based on aberrant DNA methylation of stature homeobox 2 (SHOX2) and prostaglandin E receptor 4 (PTGER4) genes with a fixed specificity of 90% and sensitivity of 67% for LC,98 while lung EpiCheck is based on the measurement of methylation level of six genes, enabling detection of up to 85% of early‐stage LC with a specificity of 64% in the high‐risk population.99 This evidence concerns the gene PTGER4 and laryngotracheoesophageal cleft.