To evaluate the role of NRG1 as a predictive biomarker for KTN3379 response in HNSCC, we evaluated KTN3379 in vivo anti-tumor activity in a panel of NRG1-positive and NRG1-negative xenograft models (Fig 3), where NRG1 expression was determined by QISH. This evidence concerns the gene NRG1 and head and neck squamous cell carcinoma.