Abstract: Protein separation by capillary electrophoresis using a buffer composition comprising hydrophobic detergents that have alkyl chains longer than 12 carbon atoms. The formation of high molecular weight artifacts is suppressed.

Abstract: CTLA-4 biomarkers useful in a method for predicting the likelihood that a mammal that will respond therapeutically to a method of treating cancer comprising administering an CTLA-4 antagonist, wherein the method comprises (a) measuring in the mammal the level of at least one biomarker s, (b) exposing a biological sample from the mammal to the CTLA-4 antagonist, and (c) following the exposing of step (b), measuring in the biological sample the level of the at least one biomarker, wherein an increase in the level of the at least one biomarker measured in step (c) compared to the level of the at least one biomarker measured in step (a) indicates an increased likelihood that the mammal will respond therapeutically to the method of treating cancer.