A significant correlation was observed between the frequency of promoter hypermethylation of RASSF1A and the differentiation degree of the tumor (χ2 = 4.932, p < 0.05), but no correlation was observed between promoter methylation of RASSF1A and the patients' age, gender, clinical stage, lymph node metastasis or distance metastasis (p > 0.05) (Table 1). The gene discussed is RASSF1; the disease is neoplasm.