Abstract: The discovery of Fc?RIIc expression on B-cells allows several new methods of prediction or regulation of immune responses. A process of altering an immune response in a subject is provided by altering the expression level or activity of Fc?RIIc on a cell. The relative ratio of activating Fc?RIIc to inhibitory Fc?RIIb levels in an immune cell allows prediction of the presence or absence of immune disease or abnormality such as rheumatoid arthritis or systemic lupus erythematosus. Inventive processes are provided whereby the relative levels of activating to inhibitory receptor expression in a subject is compared to an established inventive classification system to predict an immune response to a therapeutic, the presence or absence of disease, or the magnitude, duration, or timing of an immune response in the subject.