Most of the whole cell-based serological assays employed antigens from non-pathogenic L. biflexa serovar Patoc, with which sera from patients with leptospirosis cross-reacted, and these assays are believed to be genus-specific and detect IgM antibodies from patients, regardless of infective serovars or serogroups [17]. The gene discussed is CD40LG; the disease is leptospirosis.