One previous report found that the majority of malignant salivary gland tumors, such as mucoepidermoid carcinoma and adenoid cystic carcinoma, showed positive EZH2 immunoreactivity, but all the investigated benign tumors, including PA, were negative (55), although no SDC cases were included in that study. This evidence concerns the gene EZH2 and tumor of salivary gland.