FGFR1 and head and neck squamous cell carcinoma: Using gene expression and DNA methylation data from The Cancer Genome Atlas (TCGA) for 243 HPV-negative HNSCC pre-treatment samples [36], we verified that the upregulation of EGFR and FGFR1 is not concomitant (Pearson correlation coefficient = − 0.06, p value = 0.33, Fig. 7a).