This and the lack of response to EGFR inhibition in RT4 R1, despite the presence of major upregulation and activation of EGFR, suggest the caveat that, similar to the finding that FGFR‐mutant tumours do not all respond to FGFR inhibition, the presence of a putative predictive biomarker in many cases does not predict response. Here, EGFR is linked to neoplasm.