CD44 and head and neck squamous cell carcinoma: Similarly Szafarowski et al. compared CSC markers of HNSCC and their results revealed that ALDH1A1+ patients showed 5.25 times worse overall survival (OS) than ALDH1A1− patients (p = 0.01) and only ALDH1A1 positivity had a significant effect on OS of HNSCC patients (p = 0.02) compared to other CSC markers of CD44, CD24 and CD133 [20].