As MO-91 cells are not available in publicly accessible cell banks, and the parental MO-91 cells are poorly tumorigenic [15], we elected to evaluate merestinib and crizotinib in a HNSCC PDX model also bearing ETV6-NTRK3 gene fusion (Figure 4, Supplementary Figure 5). This evidence concerns the gene ETV6 and head and neck squamous cell carcinoma.