IL1R1 and head and neck squamous cell carcinoma: When we validated IL-1 signaling pathway by RT-PCR and ELISA, we observed a mismatch between mRNA and protein secretion of IL-1 ligands (i.e. IL-α, IL-1β, and IL-1RA) in ER- vs. ES-HNSCC cells (Figure 3A; Figure 3D-3F).