ESE3 (PSCs) had no significant correlations with gender, age, differentiation, lymph node metastasis and histologic grade but was positively correlated with pTNM (χ2 = 6.343, P = 0.012), tumour size (χ2 = 6.405, P = 0.011), CA19-9 (χ2 = 4.845, P = 0.028), carcinoembryonic antigen (CEA; χ2 = 6.060, P = 0.014) and CA242 (χ2 = 4.046, P = 0.044) (Supplementary Table S3). The gene discussed is CEACAM5; the disease is metastatic malignant neoplasm in the lymph nodes.