To further support this model, several human HNSCC cell lines were screened by Western blot analysis and prominent ALDH1A2 expression was found in FaDu, UMSCC, Detroit 562, SCC25, Lau2068, Lau2104 and Lau2105, but not Cal27, Lau2073 and Lau2081 cell lines (Fig. 2a and Additional file 3: Figure S2A-B). This evidence concerns the gene ALDH1A2 and head and neck squamous cell carcinoma.