ALDH1A1 and head and neck squamous cell carcinoma: Subsequently, we were surprised to discover that the expression of TRAF6 in SCCHN was significantly correlated with EMT markers (Vimentin, P < 0.001, r = 0.4131; Slug, P < 0.001, r = 0.6828; Fig. 5C) and CSC markers (CD44, P < 0.001, r = 0.4702; KLF4, P < 0.001, r = 0.4703; ALDH1, P < 0.001, r = 0.5452; SOX2, P < 0.001, r = 0.5895; Fig. 5C).