<qa>  What is the experimental part of this study?Using GM-CSF in NHL treatment is the experimental part of this study. In studies done in the laboratory, GM-CSF caused an increase in the number of antigens, such as CD20, on the surface of B-cells. If more antigens are present, it may be easier to target cells that express CD20 or other antigens. Monoclonal antibodies such as rituximab might then be able to more effectively bind the antigens and kill the cancer cells. 