A method of identifying a subject having cancer who is likely to benefit from treatment with a combination therapy with a MAPK pathway inhibitor, such as a RAF inhibitor, MEK inhibitor, or ERK inhibitor, and a GEF or HDAC inhibitor is provided. A method of treating cancer in a subject in need thereof is also provided and includes administering to the subject an effective amount of a MAPK inhibitor, such as a RAF inhibitor, MEK inhibitor, or ERK inhibitor, and an effective amount of a GEF or HDAC inhibitor. A method of identifying targets that confers resistance to a MAPK pathway inhibitor is also provided.
