CXCR1 and cancer: Although it has been proposed that targeting self-renewal pathways in CSCs, such as the Wnt, Notch, and Hedgehog pathways [46], or specific CSC markers, such as CD133 (Prominin-1) [47], CXCR1 [48, 49], and CD44 [50], may offer therapeutic benefits to cancer therapy, evidence for the benefits of blocking these pathways and markers in HNSCC has not been reported so far.