PGM5 and esophageal squamous cell carcinoma: To ensure the reliability and reproducibility of these seven potential lncRNA biomarkers in ESCC, we validated their expression pattern in an external Li cohort-1 (119 ESCC and 119 adjacent non-cancer controls) with a microarray platform and confirmed the same expression variation tendency of six lncRNA biomarkers (AP003548.1, PGM5-AS1, ADAMTS9-AS1, MIR503HG, LINC01082 and LINC03016) in ESCC as revealed in the SCH discovery cohort.