LAPTM5 and esophageal squamous cell carcinoma: However, we were unable to detect aberrant methylation in this region in ESCC tumors that showed low expression of LAPTM5 (data not shown), suggesting that other mechanisms, such as chromatin modification around the TSS, chromosomal deletion, or loss of transcriptional factors, may be closely associated with the down-regulation of LAPTM5 expression in ESCC tumors.