SNAI1 and neoplasm: Moreover, this phenomenon is related to the promotion of cancer stem cells (CSCs) and promotes the formation of circulating tumor cells (CTCs) through the participation of claudin-11; therefore, the overexpression of Snail and claudin-11 is related to tumor progression, recurrence, metastasis, and poor prognosis for HNSCCs [10,14,15] (Figure 1a,b).