ALDH1A1 and head and neck squamous cell carcinoma: In line with these results, cBioPortal analysis of a TCGA HNSCC data set for 517 tumor specimens showed that expression of ALDH1A3 had a tendency toward co-occurrence with CD44 expression, whereas expression of ALDH1A1 and AKT1 as well as ALDH1A1 and ALDH1A3 genes tended to be mutually exclusive (Figure 5D).