Interestingly, salivary duct carcinomas resemble breast cancer histologically, and about 20 to 80% of salivary duct carcinomas are HER2 positive by immunohistochemistry [13, 14]; in approximately 90% of salivary duct carcinomas, androgen receptors are positive by immunohistochemistry [17]. Here, ERBB2 is linked to salivary duct carcinoma.