Abstract: Provided herein are methods for identifying a cancer patient responsive to treatment with an EGFR tyrosine kinase inhibitor. One method comprises obtaining a biopsy from the patient and measuring the number of copies of miR-128b in DNA extracted from the biopsy. A patient responsive to EGFR tyrosine kinase inhibitor treatment has a cancer with less than two copies of miR-128b DNA. Another method comprises measuring miR-128b or miR-128a level in a biopsy obtained from the patient and comparing that level to miR-128b or miR-128a level in a normal tissue sample. A patient responsive to treatment with an EGFR tyrosine kinase inhibitor has a cancer expressing a lower level of miR-128b or miR-128a relative to normal tissue. Further provided herein are methods for treating cancer in a patient in need thereof. One method comprises measuring the level of miR-128b or miR-128a in a biopsy obtained from the patient and administering to the patient an EGFR tyrosine kinase inhibitor.