It is also possible that HER3 signaling has a moderate role in SCCHN and inhibition of HER3 by duligotuzumab compensated for its slightly lower affinity for EGFR (Kd of 0.4 nM vs. 0.39 nM for cetuximab) (16, 22). This evidence concerns the gene EGFR and head and neck squamous cell carcinoma.