To answer this question, we identified CD21+TIM3+ B cells in the spleen of infected dogs, suggesting that the cellular exhaustion process may also occur in B cells during the parasitism of dogs by L. infantum. Studies examining exhausted B lymphocytes expressing TIM-4+ have already been performed in mice39, but the role of TIM-3 in leishmaniasis has not yet been clarified. The gene discussed is TIMD4; the disease is leishmaniasis.