Although RASSF3 promoter hypermethylation was frequent in human pituitary somatotroph adenomas, there was no significant difference in RASSF3 expression and methylation level for different tumor grades, and RASSF3 overexpression did not affect cell invasiveness of somatotroph adenomas. The gene discussed is RASSF3; the disease is growth hormone secreting pituitary adenoma 1.