A method of identifying a subject having cancer who is likely to be responsive to a treatment compound, comprising administering the treatment compound to the subject having the cancer； obtaining a sample from the subject； determining the level of a biomarker in the sample from the subject； and diagnosing the subject as being likely to be responsive to the treatment compound if the level of the biomarker in the sample of the subject changes as compared to a reference level of the biomarker； wherein the treatment compound is a compound of Formula I:
