The present disclosure provides methods of that include detecting in a biological sample from a patient having or suspected of having cancer the presence of a polypeptide having ROS1 kinase activity or a polynucleotide encoding the same and detecting in the biological sample the presence of a mutant EGFR polypeptide or a polynucleotide encoding the same. In some aspects, the disclosure provides methods of treating a patient for cancer that include determining that a biological sample from a tumor in the patient includes a polypeptide having ROS1 kinase activity or a polynucleotide encoding the same and a mutant EGFR polypeptide or a polynucleotide encoding the same and administering to the patient a therapeutically effective amount of a ROS1 inhibitor and an EGFR inhibitor, thereby treating the patient for cancer.
