AXL and MET have been suggested to increase resistance of MAPKi and have shown synergies with MAPKi in non-HNSCC models.27 However, despite the observation of synergy between AXL/MET inhibition and trametinib combination treatment, there seemed to be a reduction in the overall AXL and MET expression in trametinib-treated cells, suggesting that the cells that are sensitive to trametinib may be the same cells that highly express AXL and MET (Supplementary Fig. S8). Here, AXL is linked to head and neck squamous cell carcinoma.