ERBB2 and carcinoma: Amplification of ERBB2 (Human Epidermal Growth Factor [HER2]) is most frequently described in typically high-grade SGC subtypes, including salivary duct carcinoma, adenocarcinoma not otherwise specified (NOS), and carcinoma ex pleomorphic adenoma, with a reported prevalence of 5–13% across all high-grade sub-types [4,5].