POU5F1 and head and neck squamous cell carcinoma: The intracellular AGR2 expression was correlated with Aldehyde Dehydrogenase 1 (ALDH1), POU class 5 homeobox 1 (Oct4), SRY-box transcription factor 2 (Sox2) and snail family transcriptional repressor 2 (Slug) in the human HNSCC tissue array [70].