HDAC1 and neoplasm: In this analysis, correlations between HDAC1 expression and tumor stage, tumor grade, lymph node metastasis or distant metastasis were observed in gastrointestinal malignancies, indicating that HDAC1 might be a good biomarker to distinguish different stages, grades, and states of lymph node metastasis or distant metastasis and would be beneficial for the diagnosis of gastrointestinal malignancy.