On the other hand, concomitant overexpression of spalt like transcription factor 4 (SALL4) and SOX2, the two main stem cell markers, was elucidated in ESCC in association with tumor invasion and aggressiveness of the disease suggesting coordination of SALL4 and SOX2 through WNT/β-catenin pathway in ESCC [30]. Here, SALL4 is linked to esophageal squamous cell carcinoma.