Disclosed herein are methods for treating an individual diagnosed with a solid tumor or a hematological malignancy, such as chronic lymphocytic leukemia (CLL), for treatment with a Brutons tyrosine kinase (BTK) inhibitor (e.g., ibrutinib) based on the expression level of miR-155. Also disclosed herein are methods for assessing whether an individual having a solid tumor or a hematological malignancy such as chronic lymphocytic leukemia (CLL) is responsive or likely to be responsive to therapy with a BTK inhibitor (e.g., ibrutinib). Further disclosed herein are methods of monitoring whether an individual receiving a BTK inhibitor (e.g., ibrutinib) for treatment of a solid tumor or a hematological malignancy such as chronic lymphocytic leukemia (CLL) has relapsed or is likely to have a relapse to therapy. Also disclosed herein are methods of selecting an individual having a solid tumor or a hematological malignancy such as chronic lymphocytic leukemia (CLL) for therapy with a BTK inhibitor (e.g., ibrutinib).
