HNSCC models expressing both NRG1 and high H11D levels demonstrated an anti-tumor response to treatment with KTN3379 in vitro, and this translated to significant single agent KTN3379 activity in cell line-derived and patient-derived HNSCC tumor xenografts in mice with the same biomarker profile (S9 Fig). The gene discussed is NRG1; the disease is head and neck squamous cell carcinoma.