We and others have recently explored the global expression profiles of ESCC with three different gene expression platforms (serial analysis of gene expression, oligonucleotide microarray, and cDNA microarray) [4-10], and have identified a multitude of genes that were overexpressed or underexpressed on transcriptional level in ESCC, compared with normal epithelia/mucosa, including Fas, FADD, caspase 8, CDC25B, fascin, CK14, CK4, annexin I, laminin-5γ2 and SPARC, encompassing a variety of functional classes. Here, KRT4 is linked to esophageal squamous cell carcinoma.