Moreover, individual antibody isotypes and their specificities, which are easily detectable and available in serum and saliva, are of particular importance for such purposes because they may also demonstrate the history of tularemia outbreak (infection’s early interval—IgM only, ongoing acute state—IgM and IgG, or infection occurred some time ago—IgG only) in the monitored area [51,58,59,60,61,62]. The gene discussed is CD40LG; the disease is infection.