RASSF1 and laryngotracheoesophageal cleft: Methylation of RASSF1A in the serum was detected in 122 of 190 (64.2 %) from patients from the HCC group, in 20 of 114 (17.5 %) patients from the LC group and in 6 of 120 (5.0 %) patients from the CHB group, but no methylation of RASSF1A was detected in the healthy controls.