This study aimed to investigate the expression of components of the RAS, by co-staining with the ESC markers SOX2 and OCT4, which were used as the surrogate markers for the OCT4+/SOX2+/KLF4+/c-MYC+ CSCs we have recently identified within the tumor nests (TNs) and the peritumoral stroma (PTS) of human HNmMM to regional lymph nodes [29]. Here, POU5F1 is linked to neoplasm.