Grouping the HNSCC cell lines based on tumourigenesity (highly tumourigenic ≤ 104 cells or poorly tumourigenic ≥ 3 × 104 cells), we were able to show an association between tumourigenesity and CEACAM6 expression (Figure1B compare High TI vs Low TI). Here, CEACAM6 is linked to head and neck squamous cell carcinoma.