To further validate the authentic effects of RIN-1, and CB-103 as specific modulators of Notch signalling in HNSCC, a series of qPCR experiments were performed, based on the expression levels of Notch-receptors themselves, and Notch-regulated or responsive genes, including HES1, HEY1, NOTCH1, NOTCH2, NOTCH3, JAG1 and DLL1 mRNA level (Fig. 2B). This evidence concerns the gene HEY1 and head and neck squamous cell carcinoma.