The present invention relates to the field of molecular biology and cancer biology. Specifically, the present invention relates to a farnesyltransferase inhibitor (FTI) for use in methods of treating squamous cell carcinoma of the head and neck (SCCHN) that is either EGFR-inhibitory refractory or that has never been treated with an EGFR inhibitor, or for use in methods of treating lung squamous cell carcinoma (lung SCC) that is either EGFR-inhibitory refractory or that has never been treated with an EGFR inhibitor, in a subject, which methods include determining whether the subject is likely to be responsive to the FTI treatment based on HRAS mutation status in the subject.
