TGFβ1 treatment increases stemness-associated marker expression in HNSCC CSCs. (A) Transcript levels of Oct4 and Sox2 in TGFβ1- or control (DMSO)-treated HNSCC CSCs. (B) ALDH activity subsequent to TGFβ1 or control (DMSO) treatment of HNSCC CSCs. TGFβ1, tumor growth factor β; HNSCC, head and neck squamous cell carcinoma; CSCs, cancer stem cells; DMSO, dimethyl sulfoxide; DEAB, diethylaminobenzaldehyde.