A third assay is an enzyme-linked dot immunoassay for IgM antibodies in serum (IgM-Enzyme-Linked ImmunoSorbent Assay [ELISA], the Dip-S-Ticks [Integrated Diagnostics, Inc., Baltimore, Maryland), that appears to have a greater sensitivity early in infection than the other available assays. The gene discussed is CD40LG; the disease is infection.