SMYD3 and head and neck squamous cell carcinoma: To assess whether SMYD3 protein levels correlate with clinicopathologic parameters of HPV-negative HNSCC patients, we utilized our previously published, clinically annotated cohort of HPV-negative HNSCC tumors (University of Chicago cohort, n = 39), which includes SMYD3 protein levels quantified by immunohistochemistry of tissue sections as previously described (IHC score scale 0–3)12 (Supplementary Table 6).