A study [26] showed that the expression rate of CD166 in head and neck squamous cell carcinomas (HNSCCs, including oral cavity, oropharynx, and hypopharynx/larynx) was up to 70.32%, and CD166 expression was significantly more frequent in malignant tissues compared with nonmalignant tissues. Here, ALCAM is linked to head and neck squamous cell carcinoma.