CD40LG and B-cell non-Hodgkin lymphoma: More surprisingly, different subclasses of IgH had contrasting biological effects on lymphoma growth, as IgG1+ cells had a significant growth disadvantage over IgM+ cells, whereas IgG3+ or IgA+ cells were positively selected (Fig. 4a-d), thus indicating that different IgH subclasses in B cell lymphoma have different biological properties.