Immunohistochemical staining scores and statistical analysis showed that PLCE1 expression levels were significantly associated with tumor differentiation (Table 1), that was, 69% of well-differentiated ESCC showed strong staining of PLCE1 (Score 3 or 2), and 31% of well-differentiated ESCC showed weak or no staining (Score 1 or 0), but 79% of poorly-differentiated ESCC showed strong staining of PLCE1 (Score 3 or 2), and 21% of poorly-differentiated ESCC showed weak or no staining (Score 1 or 0) (p = 0.038). This evidence concerns the gene PLCE1 and esophageal squamous cell carcinoma.