Accordingly, we showed that protein level of stemness signature genes (Oct-4 and Nanog) was diminished in YMGKI-2 treated sphere cells including SAS-S, OECM1-S and Primary-S (established from the primary cells derived from HNSCC tumor tissue (see Materials and Methods)) by immunoblot analyses (Figure 2C). Here, POU5F1 is linked to head and neck squamous cell carcinoma.