To explore the possible mechanism underlying the anti-CSC property of butylidenephthalide, the expression levels of the stemness marker Sox2 (sex-determining region Y (SRY)-Box2) and the EMT marker Snail were measured as these two factors have been shown to regulate several CSC features, such as self-renewal and tumorigenicity, in head and neck cancers [30,31,32]. The gene discussed is SNAI1; the disease is head and neck cancer.