CD44 and head and neck squamous cell carcinoma: Given evidence from literature of CD44 and ALDH as phenotypic markers for CSCs in HNSCC, and their significance as prognostic factors by tumour proportion [18, 26, 40, 44] this study has used concomitant elevation in CD44 and ALDH for quantification of putative CSC proportions in treated and untreated cell line cultures.