PTX3 and pneumococcal infection: During pneumococcal infection, we did not observe any difference in the levels of PTX3 in the respiratory tract and in the serum of WT mice receiving bone marrow from Ptx3−/− or WT animals, while no PTX3 was measured in Ptx3−/− mice receiving WT or Ptx3−/− bone marrow (Figure 3A, B).