When examining ctDNA alterations by histological subtype of salivary gland carcinoma, it was found that PI3KCA mutations were common in adenoid cystic carcinoma and salivary duct carcinoma, ERBB2 mutations were common in salivary gland adenocarcinoma, and EGFR mutations were common in salivary gland mucoepidermoid carcinoma [34]. The gene discussed is ERBB2; the disease is salivary gland carcinoma.