The present disclosure provides treatment modalities, e.g., strategies, treatment methods, patient stratification methods, combinations, and compositions that are useful for the treatment of disorders, e.g., proliferative disorders, such as certain cancer. Some aspects of this disclosure provide treatment modalities, methods, strategies, compositions, combinations, and dosage forms for the treatment of cell proliferative disorders, e.g., cancers, dependent upon EZH2 (enhancer of zeste 2 polycomb repressive complex 2) function with an EZH2 inhibitor.