Previous studies found a deletion at 4q21.3 in two esophageal carcinoma cell lines and found that Mapk10 was located in this deleted region with a 633bp bidirectional promoter, which was a typical CpG island, as well as that Mapk10 was expressed in all normal adult tissues (Ying et al., 2006). This evidence concerns the gene MAPK10 and carcinoma of esophagus.