HDAC1 and metastatic malignant neoplasm in the lymph nodes: An association between the low expression of HDAC1 and the presence of lymph node metastasis (p = 0.035) was indicated by univariate analysis while the high expression of HDAC1 was associated with favorable prognostic factors, such as the absence of lymph node metastasis and low mitotic index by multivariate analysis.