Objectives: HNSCC are a heterogeneous group of malignant tumors. The overexpression of EGFR coupled with ErbBs was found in over 90% of HNSCC specimens. Therefore, the therapeutic options (Cetuximab, and ibrutinib) that target EGFR inhibition have been popular choices to sensitize HNSCC cells. ErbB4 (Erb-B2 Receptor Tyrosine Kinase 4) and EGFR belong to the same family with kinase activity and interact with each other, however it is unclear the exact relationship between ErbB4 and EGFR regarding the proliferation of head and neck cancer cells, so the potential biomarker by ErbB4 and conjugation with EGFR has remained unknown. This project is intended to investigate the response of ErbB4 and EGFR of HNSCC cells to growth factors, as well as the relationship between different biochemical reagents and their efficacy in immunotherapy. Methods: SCC9 cells were cultured at 37°C, 5% CO2 in DMEM supplemented with 10% FBS, and stained with mouse anti-EGFR and rabbit anti-ErbB4. EGF (Epidermal Growth Factor) was used as a stimulator. Cetuximab (20 µg/ml) and ibrutinib (IBR: 1 µM) were used as inhibitor reagents in the experimental groups. After IHC was fully completed, the micrograph would be taken using the confocal microscope and images processed by NIH image J. Results: Essential results are listed as following: After incubation with EGF for 2 hours, the expression of ErBb4 and EGFR in SCC9 cells increased. A second group of SCC9 cells were pre-treated with Cetuximab after 2-hour incubation with EGF, and it showed that Cetuximab decreased the increasing expression of ErbB4 and EGFR caused by EGF. Another group of SCC9 cells were pre-treated with ibrutinib after 2-hour incubation with EGF. Ibrutinib showed a greater inhibition effect on blocking the increasing activities of ErbB4 and EGFR than Cetuximab. Conclusions: EGF increased the response of ErbB4 and EGFR. Ibrutinib and Cetuximab inhibited the response.