Panels a and b illustrate the IgM and IgG reactivities in the healthy and tumor-bearing mice to each antigen in a set of about 100 antigens with relatively low variation within the group of healthy mice; Panels c and d illustrate, by comparison, the IgM and IgG reactivities manifested to a set of about 100 antigens with relatively high variation. The gene discussed is CD40LG; the disease is neoplasm.