In 2004, Topaloglu O et al. examined promoter methylation status of 8 genes (CDH1, AFR, GSTP1, p16, RAR-β2, MGMT, RASSF1A, and APC) using bronchoalveolar lavage fluid from 31 LC patients and 10 age-matched controls. This evidence concerns the gene MGMT and laryngotracheoesophageal cleft.